The document discusses principles of clean code and provides examples of refactoring math functions to follow those principles. It begins with definitions of clean code and then shows how to refactor circle circumference, area, and sphere surface area/volume functions to have descriptive names, avoid literals, be self-explanatory without comments, and be easily testable. It emphasizes making code easy to understand, modify, and reuse through established conventions.
This document provides information about data types in C programming. It discusses the different data types including their size and range, as well as type modifiers. It also covers floating point numbers, character and string constants, and the char and string data types. The document describes global and local variables and declarations. Finally, it discusses enum and typedef types and different statement types in C like input, output, assignment, and control statements.
The document discusses classical encryption techniques, focusing on monoalphabetic ciphers and the Caesar cipher. It provides details on how the Caesar cipher works, including encrypting and decrypting messages by shifting letters of the alphabet based on a key. Code examples are given for implementing the Caesar cipher in a program using a dictionary to store the alphabet and encrypting/decrypting strings by adding or subtracting the key from letter numbers modulo 26.
Huffman coding is a lossless data compression algorithm that assigns variable-length codes to symbols based on their frequencies. It involves arranging symbols by probability, assigning shorter codes like 0 and 1 to more probable symbols, and combining less probable symbols into a new symbol. This process repeats until only two symbols remain, which are then assigned codes moving backward. The algorithm aims to achieve maximum efficiency by keeping code lengths short for frequent symbols and long for rare symbols. An example encodes letters A-D with probabilities 1/2, 1/4, 1/8, 1/8 into codes with lengths 1, 2, 3, and 3, achieving maximum efficiency with zero redundancy.
Huffman coding is an algorithm that uses variable-length binary codes to compress data. It assigns shorter codes to more frequent symbols and longer codes to less frequent symbols. The algorithm constructs a binary tree from the frequency of symbols and extracts the Huffman codes from the tree. Huffman coding is widely used in applications like ZIP files, JPEG images, and MPEG videos to reduce file sizes for efficient transmission or storage.
Huffman codes are a technique for lossless data compression that assigns variable-length binary codes to characters, with more frequent characters having shorter codes. The algorithm builds a frequency table of characters then constructs a binary tree to determine optimal codes. Characters are assigned codes based on their path from the root, with left branches representing 0 and right 1. Both encoder and decoder use this tree to translate between binary codes and characters. The tree guarantees unique decoding and optimal compression.
Huffman coding is a lossless data compression algorithm that uses variable-length binary codes for characters based on their frequency of occurrence, with more common characters represented by shorter bit sequences; it constructs a Huffman tree by assigning codes to characters such that the encoded output has minimum expected length, allowing for more efficient data storage and transmission. The document provides an overview of Huffman coding and trees, including an example to demonstrate how character frequencies are used to assign bit codes and compress a sample string from 56 bits to 13 bits.
This document provides information about data types in C programming. It discusses the different data types including their size and range, as well as type modifiers. It also covers floating point numbers, character and string constants, and the char and string data types. The document describes global and local variables and declarations. Finally, it discusses enum and typedef types and different statement types in C like input, output, assignment, and control statements.
The document discusses classical encryption techniques, focusing on monoalphabetic ciphers and the Caesar cipher. It provides details on how the Caesar cipher works, including encrypting and decrypting messages by shifting letters of the alphabet based on a key. Code examples are given for implementing the Caesar cipher in a program using a dictionary to store the alphabet and encrypting/decrypting strings by adding or subtracting the key from letter numbers modulo 26.
Huffman coding is a lossless data compression algorithm that assigns variable-length codes to symbols based on their frequencies. It involves arranging symbols by probability, assigning shorter codes like 0 and 1 to more probable symbols, and combining less probable symbols into a new symbol. This process repeats until only two symbols remain, which are then assigned codes moving backward. The algorithm aims to achieve maximum efficiency by keeping code lengths short for frequent symbols and long for rare symbols. An example encodes letters A-D with probabilities 1/2, 1/4, 1/8, 1/8 into codes with lengths 1, 2, 3, and 3, achieving maximum efficiency with zero redundancy.
Huffman coding is an algorithm that uses variable-length binary codes to compress data. It assigns shorter codes to more frequent symbols and longer codes to less frequent symbols. The algorithm constructs a binary tree from the frequency of symbols and extracts the Huffman codes from the tree. Huffman coding is widely used in applications like ZIP files, JPEG images, and MPEG videos to reduce file sizes for efficient transmission or storage.
Huffman codes are a technique for lossless data compression that assigns variable-length binary codes to characters, with more frequent characters having shorter codes. The algorithm builds a frequency table of characters then constructs a binary tree to determine optimal codes. Characters are assigned codes based on their path from the root, with left branches representing 0 and right 1. Both encoder and decoder use this tree to translate between binary codes and characters. The tree guarantees unique decoding and optimal compression.
Huffman coding is a lossless data compression algorithm that uses variable-length binary codes for characters based on their frequency of occurrence, with more common characters represented by shorter bit sequences; it constructs a Huffman tree by assigning codes to characters such that the encoded output has minimum expected length, allowing for more efficient data storage and transmission. The document provides an overview of Huffman coding and trees, including an example to demonstrate how character frequencies are used to assign bit codes and compress a sample string from 56 bits to 13 bits.
The document provides an overview of Huffman coding, a lossless data compression algorithm. It begins with a simple example to illustrate the basic idea of assigning shorter codes to more frequent symbols. It then defines key terms like entropy and describes the Huffman coding algorithm, which constructs an optimal prefix code from the frequency of symbols in the data. The document discusses how Huffman coding can be applied to image compression by first predicting pixel values and then encoding the residuals. It notes some disadvantages of Huffman coding and describes variations like adaptive Huffman coding.
Huffman's algorithm is a lossless data compression algorithm that assigns variable-length binary codes to characters based on their frequencies, with more common characters getting shorter codes. It builds a Huffman tree by starting with individual leaf nodes for each unique character and their frequencies, then combining the two lowest frequency nodes into an internal node until only one node remains as the root. Codes are then assigned by traversing paths from the root to leaves.
The document discusses Shannon-Fano encoding, which is an early method for data compression that constructs efficient binary codes for information sources without memory. It works by assigning shorter codes to more frequent messages and longer codes to less frequent messages. The encoding process involves recursively splitting the set of messages in half based on probability until each message has its own unique code. While Shannon-Fano codes are reasonably efficient, they are not always optimal and the codes generated can depend on how the initial splitting of messages is done.
Huffman and Arithmetic coding - Performance analysisRamakant Soni
Huffman coding and arithmetic coding are analyzed for complexity.
Huffman coding assigns variable length codes to symbols based on probability and has O(N2) complexity. Arithmetic coding encodes the entire message as a fraction between 0 and 1 by dividing intervals based on symbol probability and has better O(N log n) complexity. Arithmetic coding compresses data more efficiently with fewer bits per symbol and has lower complexity than Huffman coding asymptotically.
This document discusses the process of bringing road centerline data in-house and making it available to others. It describes past methods using Oracle views and SDE spatial views, issues with those approaches, and a new solution using Python, Parallel Python, and virtual IDs to geocode over 1.1 million records in under 2 seconds. The goal is to create a repeatable extract, load, and transform process and get the data out to others while keeping it up to date.
This presentation summarizes Huffman coding. It begins with an outline covering the definition, history, building the tree, implementation, algorithm and examples. It then discusses how Huffman coding encodes data by building a binary tree from character frequencies and assigning codes based on the tree's structure. An example shows how the string "Duke blue devils" is encoded. The time complexity of building the Huffman tree is O(NlogN). Real-life applications of Huffman coding include data compression in fax machines, text files and other forms of data transmission.
The document discusses Huffman coding, which is a data compression technique that uses variable-length codes to encode symbols based on their frequency of occurrence, with more common symbols getting shorter codes. It provides details on how a Huffman tree is constructed by assigning codes to characters based on their frequency, with the most frequent characters assigned the shortest binary codes to achieve data compression. Examples are given to demonstrate how characters are encoded using a Huffman tree and how the storage size is calculated based on the path lengths and frequencies of characters.
The document discusses Huffman coding, a lossless data compression algorithm that uses variable-length codewords to encode symbols based on their frequency of occurrence. It works by building a binary tree from the frequency of symbols, where more frequent symbols are encoded by shorter codewords. This allows for more efficient representation of frequent symbols and achieves compression close to the theoretical minimum possible given the frequencies. The algorithm and encoding/decoding process are explained step-by-step with an example.
Cassandra is a distributed, column-oriented database designed to be highly scalable and fault-tolerant. It distributes data across nodes based on the partitioner, replicates data based on the replication strategy, and achieves consistency between replicas using a combination of hinted handoffs and read repair during reads and writes. Keyspaces contain column families which store rows of columns in a flexible schema-less data model that scales horizontally by adding more nodes.
Huffman coding is a lossless data compression technique that converts fixed length codes to variable length codes. It assigns shorter codes to more frequent characters and longer codes to less frequent characters. This allows for more efficient data storage and transmission. The key steps are to create a frequency table of characters, construct a binary tree based on frequencies, and extract the Huffman codes from the tree. Huffman coding can significantly reduce file sizes by achieving better compression than fixed length codes. It is used widely in file formats like ZIP, JPEG, and MPEG.
This document summarizes Huffman code decoding. It takes a sequence to be decoded and a character probability table as input. A binary tree is built from the probabilities, with left branches representing 1 and right 0. The time complexity is O(n^2) where n is the sequence length, as building the tree can resemble an unbalanced tree. Sample run times are provided for sequences of different lengths on 10 possible characters. Pseudocode provides an algorithm to traverse the tree and decode the sequence.
Functions: Function Definition, prototyping, types of functions, passing arguments to functions, Nested Functions, Recursive functions.
Strings: Declaring and Initializing strings, Operations on strings, Arrays of strings, passing strings to functions. Storage Classes: Automatic, External, Static and Register Variables.
This document provides an overview of file input/output in C including opening, reading, writing, and closing files. It discusses sequential and random access of files. Key functions covered include fopen(), fclose(), fgets(), fputs(), fscanf(), fprintf(), fseek(), rewind(), and their usage. Examples and exercises are provided to demonstrate reading/writing contents, formatted and unformatted I/O, and random access in files.
This document discusses various topics in network security including cryptography, symmetric and asymmetric encryption algorithms, digital signatures, and firewalls. It provides detailed explanations and examples of symmetric key algorithms like monoalphabetic and polyalphabetic substitution ciphers, transpositional ciphers, and block ciphers like DES. It also covers asymmetric key algorithms like RSA and their use for encryption and digital signatures. Finally, it describes packet filter and proxy based firewalls and how they can be used to control network access.
This document provides an introduction to arithmetic coding, a data compression technique. It begins with an abstract, introduction, and overview of arithmetic coding and how it differs from other entropy encoding techniques like Huffman coding. It then goes into more detail about the basic concepts, motivation, and methods behind arithmetic coding over multiple chapters. It discusses how arithmetic coding encodes data by creating a code that represents a fraction in the unit interval [0,1] and recursively partitions this interval based on the input symbols. The document provides examples to illustrate how arithmetic coding works and generates unique tags for symbol sequences.
The document provides an overview of the C and C++ programming languages. It discusses the history and evolution of C and C++. It describes key features of C like procedural programming, manual memory management, and lack of object orientation. It also describes features of C++ like classes, inheritance, and templates which provide object orientation. The document lists many widely used software written in C/C++ and discusses advantages like speed and compact memory usage and disadvantages like difficulty of manual memory management. It provides examples of basic C code structures and data types.
Structures-Declaring and Initializing, Nested structure, Array of Structure, Passing Structures to functions, Unions, typedef, enum, Bit fields.
Pointers: Declarations, Pointer arithmetic, Pointers and functions, call by value, Call by reference, Pointers and Arrays, Arrays of Pointers, Pointers and Structures. Meaning of static and dynamic memory allocation, Memory allocation functions.
Files: File modes, File functions, and File operations, Text and Binary files, Command Line arguments Preprocessor directives. Macros: Definition, types of Macros, Creating and implementing user defined header files
The document discusses various lossless compression techniques including entropy coding methods like Huffman coding and arithmetic coding. It also covers dictionary-based coding like LZW, as well as spatial compression techniques like run-length coding, quadtrees for images, and lossless JPEG.
Data Communication & Computer network: Shanon fano codingDr Rajiv Srivastava
These slides cover the fundamentals of data communication & networking. it covers Shanon fano coding which are used in communication of data over transmission medium. it is useful for engineering students & also for the candidates who want to master data communication & computer networking.
Use of an Oscilloscope - maXbox Starter33Max Kleiner
This is an oscilloscope introduction that uses several sources for input. My hope is that it encourages a few future scientists to experiment and get into touch with new waves ~.
Oscilloscopes are one of the few pieces of electronic equipment that plays multiple roles and can be used in the place of other electronics equipment.
The document outlines an Arduino training class taught by Max Kleiner on May 21, 2014. The one-day class goals are to introduce students to the Arduino, show cool projects, set up the Arduino IDE, upload code to an Arduino Uno, and complete basic tutorials like blinking LEDs. The document also lists recommended Arduino learning resources and tutorials, applications like light and motor control, and encourages students to let their imagination guide their projects.
The document provides an overview of Huffman coding, a lossless data compression algorithm. It begins with a simple example to illustrate the basic idea of assigning shorter codes to more frequent symbols. It then defines key terms like entropy and describes the Huffman coding algorithm, which constructs an optimal prefix code from the frequency of symbols in the data. The document discusses how Huffman coding can be applied to image compression by first predicting pixel values and then encoding the residuals. It notes some disadvantages of Huffman coding and describes variations like adaptive Huffman coding.
Huffman's algorithm is a lossless data compression algorithm that assigns variable-length binary codes to characters based on their frequencies, with more common characters getting shorter codes. It builds a Huffman tree by starting with individual leaf nodes for each unique character and their frequencies, then combining the two lowest frequency nodes into an internal node until only one node remains as the root. Codes are then assigned by traversing paths from the root to leaves.
The document discusses Shannon-Fano encoding, which is an early method for data compression that constructs efficient binary codes for information sources without memory. It works by assigning shorter codes to more frequent messages and longer codes to less frequent messages. The encoding process involves recursively splitting the set of messages in half based on probability until each message has its own unique code. While Shannon-Fano codes are reasonably efficient, they are not always optimal and the codes generated can depend on how the initial splitting of messages is done.
Huffman and Arithmetic coding - Performance analysisRamakant Soni
Huffman coding and arithmetic coding are analyzed for complexity.
Huffman coding assigns variable length codes to symbols based on probability and has O(N2) complexity. Arithmetic coding encodes the entire message as a fraction between 0 and 1 by dividing intervals based on symbol probability and has better O(N log n) complexity. Arithmetic coding compresses data more efficiently with fewer bits per symbol and has lower complexity than Huffman coding asymptotically.
This document discusses the process of bringing road centerline data in-house and making it available to others. It describes past methods using Oracle views and SDE spatial views, issues with those approaches, and a new solution using Python, Parallel Python, and virtual IDs to geocode over 1.1 million records in under 2 seconds. The goal is to create a repeatable extract, load, and transform process and get the data out to others while keeping it up to date.
This presentation summarizes Huffman coding. It begins with an outline covering the definition, history, building the tree, implementation, algorithm and examples. It then discusses how Huffman coding encodes data by building a binary tree from character frequencies and assigning codes based on the tree's structure. An example shows how the string "Duke blue devils" is encoded. The time complexity of building the Huffman tree is O(NlogN). Real-life applications of Huffman coding include data compression in fax machines, text files and other forms of data transmission.
The document discusses Huffman coding, which is a data compression technique that uses variable-length codes to encode symbols based on their frequency of occurrence, with more common symbols getting shorter codes. It provides details on how a Huffman tree is constructed by assigning codes to characters based on their frequency, with the most frequent characters assigned the shortest binary codes to achieve data compression. Examples are given to demonstrate how characters are encoded using a Huffman tree and how the storage size is calculated based on the path lengths and frequencies of characters.
The document discusses Huffman coding, a lossless data compression algorithm that uses variable-length codewords to encode symbols based on their frequency of occurrence. It works by building a binary tree from the frequency of symbols, where more frequent symbols are encoded by shorter codewords. This allows for more efficient representation of frequent symbols and achieves compression close to the theoretical minimum possible given the frequencies. The algorithm and encoding/decoding process are explained step-by-step with an example.
Cassandra is a distributed, column-oriented database designed to be highly scalable and fault-tolerant. It distributes data across nodes based on the partitioner, replicates data based on the replication strategy, and achieves consistency between replicas using a combination of hinted handoffs and read repair during reads and writes. Keyspaces contain column families which store rows of columns in a flexible schema-less data model that scales horizontally by adding more nodes.
Huffman coding is a lossless data compression technique that converts fixed length codes to variable length codes. It assigns shorter codes to more frequent characters and longer codes to less frequent characters. This allows for more efficient data storage and transmission. The key steps are to create a frequency table of characters, construct a binary tree based on frequencies, and extract the Huffman codes from the tree. Huffman coding can significantly reduce file sizes by achieving better compression than fixed length codes. It is used widely in file formats like ZIP, JPEG, and MPEG.
This document summarizes Huffman code decoding. It takes a sequence to be decoded and a character probability table as input. A binary tree is built from the probabilities, with left branches representing 1 and right 0. The time complexity is O(n^2) where n is the sequence length, as building the tree can resemble an unbalanced tree. Sample run times are provided for sequences of different lengths on 10 possible characters. Pseudocode provides an algorithm to traverse the tree and decode the sequence.
Functions: Function Definition, prototyping, types of functions, passing arguments to functions, Nested Functions, Recursive functions.
Strings: Declaring and Initializing strings, Operations on strings, Arrays of strings, passing strings to functions. Storage Classes: Automatic, External, Static and Register Variables.
This document provides an overview of file input/output in C including opening, reading, writing, and closing files. It discusses sequential and random access of files. Key functions covered include fopen(), fclose(), fgets(), fputs(), fscanf(), fprintf(), fseek(), rewind(), and their usage. Examples and exercises are provided to demonstrate reading/writing contents, formatted and unformatted I/O, and random access in files.
This document discusses various topics in network security including cryptography, symmetric and asymmetric encryption algorithms, digital signatures, and firewalls. It provides detailed explanations and examples of symmetric key algorithms like monoalphabetic and polyalphabetic substitution ciphers, transpositional ciphers, and block ciphers like DES. It also covers asymmetric key algorithms like RSA and their use for encryption and digital signatures. Finally, it describes packet filter and proxy based firewalls and how they can be used to control network access.
This document provides an introduction to arithmetic coding, a data compression technique. It begins with an abstract, introduction, and overview of arithmetic coding and how it differs from other entropy encoding techniques like Huffman coding. It then goes into more detail about the basic concepts, motivation, and methods behind arithmetic coding over multiple chapters. It discusses how arithmetic coding encodes data by creating a code that represents a fraction in the unit interval [0,1] and recursively partitions this interval based on the input symbols. The document provides examples to illustrate how arithmetic coding works and generates unique tags for symbol sequences.
The document provides an overview of the C and C++ programming languages. It discusses the history and evolution of C and C++. It describes key features of C like procedural programming, manual memory management, and lack of object orientation. It also describes features of C++ like classes, inheritance, and templates which provide object orientation. The document lists many widely used software written in C/C++ and discusses advantages like speed and compact memory usage and disadvantages like difficulty of manual memory management. It provides examples of basic C code structures and data types.
Structures-Declaring and Initializing, Nested structure, Array of Structure, Passing Structures to functions, Unions, typedef, enum, Bit fields.
Pointers: Declarations, Pointer arithmetic, Pointers and functions, call by value, Call by reference, Pointers and Arrays, Arrays of Pointers, Pointers and Structures. Meaning of static and dynamic memory allocation, Memory allocation functions.
Files: File modes, File functions, and File operations, Text and Binary files, Command Line arguments Preprocessor directives. Macros: Definition, types of Macros, Creating and implementing user defined header files
The document discusses various lossless compression techniques including entropy coding methods like Huffman coding and arithmetic coding. It also covers dictionary-based coding like LZW, as well as spatial compression techniques like run-length coding, quadtrees for images, and lossless JPEG.
Data Communication & Computer network: Shanon fano codingDr Rajiv Srivastava
These slides cover the fundamentals of data communication & networking. it covers Shanon fano coding which are used in communication of data over transmission medium. it is useful for engineering students & also for the candidates who want to master data communication & computer networking.
Use of an Oscilloscope - maXbox Starter33Max Kleiner
This is an oscilloscope introduction that uses several sources for input. My hope is that it encourages a few future scientists to experiment and get into touch with new waves ~.
Oscilloscopes are one of the few pieces of electronic equipment that plays multiple roles and can be used in the place of other electronics equipment.
The document outlines an Arduino training class taught by Max Kleiner on May 21, 2014. The one-day class goals are to introduce students to the Arduino, show cool projects, set up the Arduino IDE, upload code to an Arduino Uno, and complete basic tutorials like blinking LEDs. The document also lists recommended Arduino learning resources and tutorials, applications like light and motor control, and encourages students to let their imagination guide their projects.
1) The document provides an introduction to programming with the maXbox tool. It explains the interface and how to load sample code.
2) The sample code checks if numbers are prime by using a function called checkPrim() within a procedure called TestPrimNumbers(). It saves the results to a file.
3) The main routine calls TestPrimNumbers(), saves the output list to a file, loads the file, and displays the results along with performance times. This demonstrates functions, procedures, file I/O, and other basic programming concepts.
The document discusses the Delphi Runtime Library (RTL). It provides three key points:
1. The RTL is a collection of functions and procedures built into Delphi that are organized into units like SysUtils, Classes, and FileCtrl.
2. The SysUtils unit is well documented and contains many commonly used routines.
3. The RTL aims to be platform independent through conditional compilation and provides object wrappers for many routines through units like Contnrs.
A Global Positioning System (GPS) is a space-based satellite navigation system that provides location and time information in all weather conditions,
but how does it work?
There are three main topics in here. First technologies – simply put, this part is mainly for early adopters. It’s about coding, developing toys, plugging in kettles on the web (and we and many others actually did that!).
The second part is about new ideas, prototyping and new technologies that are in the lab. It’s about research papers, and software philosophy, and about researchers worldwide. Third part is about end-users and products.
This document provides information on developing a Web of Things (WoT) including:
- Discussing how to get started with programming "things" like Arduino, Raspberry Pi, and SunSpot boards.
- Describing the complex process of programming microcontrollers, including using IDEs, compilers, debuggers, and loading code.
- Outlining key questions to answer before starting a WoT project, such as the scope, use case, programming tools, and publishing infrastructure.
- Providing an example WoT use case of using distributed sensing for applications like power grids, transport systems, and industrial automation.
The document discusses a TCP server and client example for looking up zip codes. It provides code for a server that listens for connections on port 6000 and responds to "ZipCode" and "Quit" commands by looking up zip codes from a file and disconnecting. It also provides code for a client that connects to the server, sends zip code lookup requests, reads the responses, and disconnects. Key aspects covered include using blocking sockets, threading models in Indy servers, and how the examples can be tested using Telnet.
1. The document introduces programming and time travel by having the reader code a clock app in maXbox that outputs the time and travels into the past.
2. It begins with the basics of programming tools, variables, constants, and loops. It then has the reader add time functions to output with the clock.
3. Further iterations have the clock loop for longer durations and travel back in time faster by changing function parameters and variables.
4. By the end, the clock code introduces parameters to flexibly control the time travel speed and duration, outputting dates thousands of years into the past.
This document provides instructions for using WinCOM (Component Object Model) to export data from an Arduino motor controller application to an Excel spreadsheet. It discusses:
1) Using WinCOM to export data from the application to cells in an Excel spreadsheet by creating an Excel object and filling cells.
2) Controlling a DC motor with an Arduino board and sending motor data back to be exported to an Excel file.
3) Configuring COM port settings to communicate between the Arduino and computer for sending and receiving data.
We code a RGB LED light on the Arduino board and a breadboard on which we switch off or on the light by a browser on an android device with our own web server and their COM protocols.
The document discusses using APIs to create graphical user interfaces in Windows programs. It provides an example of using the WNetConnectionDialog API function to start a network connection dialog box. The function requires a window handle and resource type as parameters. It returns error codes like NO_ERROR if successful. The document also discusses getting window handles, declaring external functions, and writing logs to the Windows event log using the API.
RGB LED in Arduino with an Oscilloscope
• Generating QR Code
• 3D Printing
• Web Video Cam
• Digi Clock with Real Time Clock
• Android SeekBar to Arduino LED Matrix
This document discusses CODEsign, which involves designing functions twice to simplify them and improve performance. It recommends designing functions twice with the same result, checking functions twice to compare results, proving concepts twice, testing functions twice, documenting and saving code twice, visualizing solutions twice, and teaching concepts twice. CODEsign can be applied to problems like spam filtering, computer vision, speech recognition, and more. The document was written by Max Kleiner of softwareschule.ch.
The Doodle3D WiFi-Box makes almost all 3D printers wirelessly controllable through a simple REST API. This means you can control them
using Processing, openFrameworks, JavaScript, Arduino, Delphi, Cinder etc. Basically any language that can send and receive HTTP requests (AJAX).
Arduino C maXbox web of things slide showMax Kleiner
This document discusses using Arduino and C# for internet of things projects. It provides an overview of starter kits for learning electronics and gives examples of blinking LED projects. It also lists components needed for a 4-digit LED display project and provides code samples for setting the time on an Arduino from a PC and encrypting/decrypting data.
C is a general-purpose programming language widely used to develop operating systems and compilers. It was developed in the early 1970s at Bell Labs by Dennis Ritchie. Some key reasons for C's popularity include its efficiency, ability to access low-level hardware, and ability to be compiled on a variety of computers. C source code files use a .c extension and must be compiled into an executable binary file before running. Common uses of C include operating systems, language compilers, databases, and network drivers.
The document discusses editing, compiling, and executing a simple C++ program. It begins with an overview of basic C++ programming elements and concepts like tokens, data types, arithmetic operators, and precedence. It then provides examples of simple C++ programs that perform arithmetic calculations and output results. The document emphasizes that understanding programming fundamentals like variables, data types, expressions, and control flow is necessary before writing even basic C++ programs.
The C is a general-purpose, procedural, imperative computer programming language developed in 1972 by Dennis Ritchie at the Bell Telephone Laboratories for use with the Unix operating system.
Here is the class Book with the requested attributes and member functions:
#include <iostream>
using namespace std;
class Book {
private:
string title;
string author;
string publisher;
float price;
public:
Book() {
title = "No title";
author = "No author";
publisher = "No publisher";
price = 0.0;
}
void display_data() {
cout << "Title: " << title << endl;
cout << "Author: " << author << endl;
cout << "Publisher: " << publisher << endl;
cout << "Price: " << price << endl;
}
This material is developed in such beautiful manner to the beginners of C language can understand it accurately.
Every concept In material is explained in well disciplined.
Even it will be helpful to the professors for presenting lecture in class room
This document provides an overview of the C++ programming language including its history, common features, and useful resources for learning C++. It discusses data types, classes, functions, pointers, references, operator overloading, templates, and more. Code examples are provided to illustrate key concepts. Useful online tutorials and references are listed for further learning C++.
- All variables in a C program must be declared before they can be used, specifying a name, value, and type.
- The document discusses basic C programming concepts like variables, data types, comments, functions, and arithmetic expressions.
- It provides examples of C code snippets and explains concepts like preprocessing, compiling, linking, and executing a C program.
This document provides an overview of a C programming lesson that covers various topics including printing text, data types, the sizeof operator, GCC parameters, coding style, standard library headers, and return values from the main function. It contains slides on C programming fundamentals, learning objectives, quiz questions, and a link to additional slides. The hands-on lab practice section allows the learner to put the concepts into practice.
The document provides an overview of the C standard library. It includes a table listing common C standard library header files and briefly describing their purpose, such as <stdio.h> for input/output functions and <stdlib.h> for memory allocation and process control. The C standard library contains functions for tasks like string manipulation, mathematics, random numbers, memory management and more. It provides a standard library that is common across C implementations.
The document provides an introduction to the basic structure of C++ programs. It defines key elements such as comments, preprocessor directives, header files, the main function, and return statements. It also explains identifier naming rules and how to declare variables according to standards. Specifically, it states identifiers can include letters, digits and underscores but not special characters or spaces. Variables must be declared before use with a data type and name following the rules. The document is teaching the fundamentals of C++ programming syntax and structure.
This document provides an introduction and overview of the C programming language. It discusses what a computer is and how programming languages work. It introduces machine language and high-level languages like C. Key aspects of C are explained, including data types, variables, operators, functions, and basic syntax. Examples of simple C programs are provided.
C was developed in the 1970s and is a popular and widely used programming language today. It is well-suited for systems programming and embedded systems due to its portability, efficiency, and ability to access hardware. A C program consists of functions written in a logical sequence to perform tasks. The main function is the starting point and every program must contain one. C programs are compiled in two steps - preprocessing and compilation - to create an executable binary file.
C was developed in the 1970s and is a popular programming language used widely for systems programming and other applications. The document discusses the history and characteristics of C, the structure of C programs including functions and files used, basic syntax elements like variables, data types, constants and comments. It also covers compiling and executing C programs.
C is a general-purpose programming language developed in the early 1970s. It was originally created for and used to write the UNIX operating system. C became widely popular due to its efficiency and ability to be compiled on a variety of computers. It is commonly used to write operating systems, compilers, and other lower-level systems programs. C programs are written in text files with a .c extension and compiled into machine-readable code using a C compiler. C supports basic data types like integers, floats, characters, and arrays, as well as user-defined functions, variables, statements, and expressions.
Chapter-2 edited on Programming in Can refer this pptANISHYAPIT
C was developed in the 1970s and is a popular and widely used programming language today. It is well suited for systems programming due to its portability, efficiency, and ability to access hardware. A C program consists of functions written in a logical sequence to perform tasks. Key aspects of C include its small size, support for pointers and structures, and suitability for both low-level and structured programming.
The document discusses the Objective-C preprocessor and underlying C language features. It covers preprocessor directives like #define, #import, #include, and #undef. It also discusses arrays, structures, pointers, functions, and how Objective-C works with C at a low level. Blocks in Objective-C are described as being similar to functions but having some differences like needing to be declared in .m files instead of .h headers.
The document provides an introduction to computer programming and the C++ programming language. It discusses what a computer program is, different types of programs, and the process of computer programming. It then covers key concepts in C++ programming including data types, variables, constants, input/output, and basic program structure. The document is intended to teach programming fundamentals and provide an overview of C++ for beginners.
The document provides an introduction to the C programming language, including its history and evolution. It discusses key elements of C programs like main functions, libraries, headers, source/header files. It also covers basic C concepts like data types, variables, operators, functions, pointers, arrays, comments and preprocessor directives. Examples of simple C programs are provided to illustrate these concepts.
The document provides an introduction to the C programming language, including its history and evolution. It discusses key elements of C programs like functions, variables, data types, comments, preprocessor directives, libraries and headers. It also covers pointers, arrays, passing command line arguments and standard header files in C. Examples of simple C programs are provided to illustrate various concepts.
The document provides an introduction to the C programming language, including its history and evolution. It discusses key elements of C programs like functions, variables, data types, libraries, headers, and compilers. It also covers pointers, arrays, preprocessor directives, and macros. Examples are provided to illustrate basic C programs and common programming constructs in C.
Similar to Clean Code Tutorial maXbox starter24 (20)
In the last sessions we have seen that P4D (Python 4 Delphi) is powerful enough to offer components, Python packages or libraries in Delphi or Lazarus (FPC). This time we go the other way of usage and integration; how does the Python or web world in the shell benefit from the VCL components as GUI controls. We create a Python extension module from Delphi classes, packages or functions. Building Delphi’s VCL library as a specific Python module in a console or editor and launching a complete Windows GUI from a script can be the start of a long journey.
The flood of Open APIs is now so blatant that we take a closer look at some basics and principles. Of course, the best way to understand how APIs work is to try them. While most APIs require access via API keys or have complicated authentication and authorization methods, there are also open APIs with no requirements or licenses whatsoever. This is especially useful for beginners as we can start exploring different APIs right away. It’s also useful for web developers who want easy access to a sample dataset for their app; e.g. most weather apps get their weather forecast data from a weather API instead of building weather stations themselves.
Faker is a Python library that generates fake data. Fake data is often used for testing or filling databases with some dummy data. Faker is heavily inspired by PHP's Faker, Perl's Data::Faker, and by Ruby's Faker.
Many of the applications and organizations provide avatar features. Finally, synthetic datasets can minimize privacy concerns. Attempts to anonymize data can be ineffective, as even if sensitive/identifying variables are removed from the dataset
Python for Delphi (P4D) is a set of free components that wrap up the Python DLL into Delphi and Lazarus (FPC). They let you easily execute Python scripts, create new Python modules and new Python types. You can create Python extensions as DLLs and much more like scripting. P4D provides different levels of functionality: Low-level access to the python API High-level bi-directional interaction with Python Access to Python objects using Delphi custom variants (VarPyth.pas).
Python for Delphi (P4D) is a set of free components that wrap up the Python DLL into Delphi and Lazarus (FPC). They let you easily execute Python scripts, create new Python modules and new Python types. You can create Python extensions as DLLs and much more like scripting. P4D provides different levels of functionality:
Low-level access to the python API
High-level bi-directional interaction with Python
Access to Python objects using Delphi custom variants (VarPyth.pas)
Wrapping of Delphi objects for use in python scripts using RTTI (WrapDelphi.pas)
Creating python extension modules with Delphi classes and functions
Generate Scripts in maXbox from Python Installation
The document describes steps to build and train an image classification model using Lazarus, the neural-api library, and Google Colab. It clones the neural-api GitHub repository, installs dependencies like FPC and Lazarus, builds and trains a simple image classifier on the CIFAR-10 dataset, and exports the trained model weights and training logs. The process demonstrates how to leverage Google Colab's GPUs to train deep learning models using Lazarus and Pascal.
The portable pixmap format(PPM), the portable graymap format(PGM) and portable bitmap format(PBM) are image file formats designed to be easily exchanged between platforms. They are also sometimes referred collectively as the portable anymap format(PNM). These formats are a convenient (simple) method of saving image data. And the format is not even limited to graphics, its definition allowing it to be used for arbitrary three-dimensional matrices or cubes of unsigned integers.
This tutor puts a trip to the kingdom of object recognition with computer vision knowledge and an image classifier.
Object detection has been witnessing a rapid revolutionary change in some fields of computer vision. Its involvement in the combination of object classification
as well as object recognition makes it one of the most challenging topics in the domain of machine learning & vision.
How can we visualize data in machine learning with VS Code? This is a C# wrapper for the GraphViz graph generator for dotnet core. Further bindings for Python GraphViz are shown and exports to MS Power BI all in MS Visual Code, Jupyter and dotnet core.
K-CAI NEURAL API is a Keras based neural network API for machine learning that will allow you to prototype with a lots of possibilities of Tensorflow! Python, Free Pascal and Delphi together in Google Colab, Git or the Community Edition.
Software is changing the world. CGC is a Common Gateway Coding as the name says, it is a "common" language approach for almost everything. I want to show how a multi-language approach to infrastructure as code using general purpose programming languages lets cloud engineers and code producers unlocking the same software engineering techniques commonly used for applications.
Code Review Checklist: How far is a code review going? "Metrics measure the design of code after it has been written, a Review proofs it and Refactoring improves code."
In this paper a document structure is shown and tips for a code review.
Some checks fits with your existing tools and simply raises a hand when the quality or security of your codebase is impaired.
Open LDAP as A directory serviceis a system for storing and retrieving information in a tree-like structure with the following key properties:
Optimized for reading Distributed storage model Extensible data storage types Advanced search capabilities Consistent replication possibilities
This document discusses closures and functional programming. It begins with an agenda that covers closures as code blocks, their history in languages like Lisp and Scheme, examples of functional programming, and using closures for refactoring. It then discusses a case study on experiences with a polygraph design, including optimizations with closures, packaging, and applying the Demeter principle. Finally, it provides links for further reading on closures.
This document explains how to redirect console output from a GUI application to the parent command prompt process. It describes using the AttachConsole and FreeConsole functions to attach and detach a process from the console. The GetParentProcessName function is used to get the name of the parent process (e.g. cmd.exe or powershell.exe) to determine if output should be redirected. The code sample shows attaching the console, writing sample output, and detaching when complete.
Introduction to use machine learning in python and pascal to do such a thing like train prime numbers when there are algorithms in place to determine prime numbers. See a dataframe, feature extracting and a few plots to re-search for another hot experiment to predict prime numbers.
This tutor shows the train and test set split with binary classifying, clustering and 3D plots and discuss a probability density function in scikit-learn on synthetic datasets. The dataset is very simple as a reference of understanding.
This document discusses machine learning techniques including linear support vector machines (SVMs), data splitting, model fitting and prediction, and histograms. It summarizes an SVM tutorial for predicting samples and evaluating models using classification reports and confusion matrices. It also covers kernel density estimation, PCA, and comparing different classifiers.
In this article you will learn hot to use tensorflow Softmax Classifier estimator to classify MNIST dataset in one script.
This paper introduces also the basic idea of a artificial neural network.
The term “machine learning” is used to describe one kind of “artificial intelligence” (AI) where a machine is able to learn and adapt through its own experience. We crawled and collected 30 top overview diagrams which shows the topic of methods, algorithms and concepts.
You may be stressed about revealing your cancer diagnosis to your child or children.
Children love stories and these often provide parents with a means of broaching tricky subjects and so the ‘The Secret Warrior’ book was especially written for CANSA TLC, by creative writer and social worker, Sally Ann Carter.
Find out more:
https://cansa.org.za/resources-to-help-share-a-parent-or-loved-ones-cancer-diagnosis-with-a-child/
Covey says most people look for quick fixes. They see a big success and want to know how he did it, believing (and hoping) they can do the same following a quick bullet list.
But real change, the author says, comes not from the outside in, but from the inside out. And the most fundamental way of changing yourself is through a paradigm shift.
That paradigm shift is a new way of looking at the world. The 7 Habits of Highly Effective People presents an approach to effectiveness based on character and principles.
The first three habits indeed deal with yourself because it all starts with you. The first three habits move you from dependence from the world to the independence of making your own world.
Habits 4, 5 and 6 are about people and relationships. The will move you from independence to interdependence. Such, cooperating to achieve more than you could have by yourself.
The last habit, habit number 7, focuses on continuous growth and improvement.
Aggression - Applied Social Psychology - Psychology SuperNotesPsychoTech Services
A proprietary approach developed by bringing together the best of learning theories from Psychology, design principles from the world of visualization, and pedagogical methods from over a decade of training experience, that enables you to: Learn better, faster!
Understanding of Self - Applied Social Psychology - Psychology SuperNotesPsychoTech Services
A proprietary approach developed by bringing together the best of learning theories from Psychology, design principles from the world of visualization, and pedagogical methods from over a decade of training experience, that enables you to: Learn better, faster!
ProSocial Behaviour - Applied Social Psychology - Psychology SuperNotesPsychoTech Services
A proprietary approach developed by bringing together the best of learning theories from Psychology, design principles from the world of visualization, and pedagogical methods from over a decade of training experience, that enables you to: Learn better, faster!
ProSocial Behaviour - Applied Social Psychology - Psychology SuperNotes
Clean Code Tutorial maXbox starter24
1. maXbox Starter 24
Start with Clean Code
1.1 From Archimedes to PI
Today we dive into Clean Code and Refactoring. Robert C. Martin offers in the first chapter of his
book 'Clean Code' several definitions of 'clean code' from different well known software experts.
So what’s Clean Code in my opinion?
•
•
•
•
•
Easy to understand and comprehensible.
Easy to modify.
Simple to test.
Uncomplicated reuse.
And works correctly (Kent Beck's suggestion).
Interesting point is also the comment behind the code. The less comment you have could be a
sign of code that doesn't require any comments to be easily understood.
I mean you can comment like this “//very tricky section…” which is a comment but makes
less sense. On the other side we can find code so understandable, that it doesn’t need additional
comment so we come to the first law of clean code:
Code has to be self explanatory.
Code which reads as close to a human language as possible. We mean it on all the levels: from
syntax used, naming convention and alignment of source all the way to algorithms used quality of
comments and complexity of distribution of code between modules.
Let’s put a first example:
if (S_OK:= strFNA.find(0, ‘the sign of the cross’))
This line isn’t really readable let’s put it this way:
if (filename.contains(‘the sign of the cross’))
There a lot of design principles that we already know and apply rigorously throughout tons of
software design, but most importantly, the way to simplicity aren’t that simple!
Clean Code also proposes most of all 3 principles:
1. Code Conventions
2. Design Patterns
3. Convention over Configuration
I will show you this with a topic in math; a few equations with PI:
2. How do we compute the circumference of a circle? The circumference of a circle is the distance
around the edge of the circle. You compute: C=d*PI
[d=Diameter]
The diameter of a circle is the distance from one edge to the other, through the centre.
Now let’s put this in a function:
147: function circleCircumference(dia: double): double;
148: begin
149:
result:= dia * PI;
150: end;
Is this really Clean Code; yes or no? PI is a constant so it has to be set in uppercase (code
conventions). But what about Dia is this understandable? Avoid using the same word for two
purposes, so Dia could mean another fact. Name it like it is:
151: function circleCircumference(diameter: double): double;
152: begin
153:
result:= diameter * PI;
154: end;
Therefore you can avoid comments and the function is small enough to be understood. Next you
want to compute the area of a circle. The area of a circle is the number of square units inside that
circle. You compute: A=r^2*PI
[d=2*r] [r=d/2]
155: function circleArea(diameter: double): double;
156: begin
157:
result:= Power(diameter/2,2) * PI;
158: end;
Do we also use the reuse of that function? Think about a way to reuse our primary
Circumference function as a baseline:
159: function circleAreaReuse(diameter: double): double;
160: begin
161:
result:= Power(circleCircumference(diameter)/2/PI,2) * PI;
162: end;
But I mean this function is less readable than the previous one. So what is it that makes a
function like the first one easy to read and understand? It must be small with descriptive names
and parameters and can also profit of reuse like code blocks or closures.
That’s the second law of clean code:
Functions should be small.
Next as we state before a function should also be testable.
We know from the last function that the diameter of a circle is twice as long as the radius. In math
there exists the unit circle with radius equals 1. And with this in mind all the functions with radius
= 1 results in PI or should do so!
//Test Drive
writeln(floatToStr(circleCircumference(1)));
writeln(floatToStr(circleArea(2*1)));
writeln(floatToStr(circleAreaReuse(2*1)));
PrintF('%.14f',[circleArea(2*1)]);
Better is an assert statement:
570: Assert(floatToStr(circleArea(2*1))=floatToStr(PI),'assert PI false');
We use the Greek letter Pi (pronounced Pi) to represent the ratio of the circumference of a circle
to the diameter. For simplicity, we use Pi = 3.14159265358979 to compare. Pi itself is irrational.
2
3. Last in this math clean code lesson we jump to 3D and calculate the surface of a circle in that
sense a sphere. This relationship is expressed in the following formula:
S=4*r^2*PI
[4*A]
163: function SphereSurface(diameter: double): double;
164: begin
165:
result:= 4*circleArea(diameter);
166: end;
I think that’s comprehensible the surface is 4 times the area of a circle; and the test function unit:
578: Assert(floatToStr(sphereSurface(2*1))=floatToStr(PI*4),'Surface F');
However, it is easier to use the calculator ;-).
Let me say one note about the reuse or inheritance of the function circleAreaReuse.
It’s not so understandable how the equation works. In this case a comment must be. Given the
radius or diameter of a circle, we can find its area. We can also find the radius1 (and diameter) of
a circle given its area, so let’s stick some comment together (D=C/PI):
159:
160:
163:
164:
165:
function circleAreaReuse(diameter: double): double;
begin
// Given radius (diameter/2) of circle, we can find area.
result:= Power(circleCircumference(diameter)/2/PI,2) * PI;
end;
You may know that the story goes on. You can compute as a next step the volume of a sphere:
(V=4/3*PI*r^3)
172: function sphereVolume(diameter: double): double;
173: begin
174:
result:= 4/3*circleArea(diameter)*(diameter/2);
175: end;
A further discussion could be the comparison of the reuse function or the straight function:
172: function Volume(diameter: double): double;
173: begin
174:
result:= 4/3*PI * Power(diameter/2,3);
175: end;
Which is more readable or easier to modify? Or why not use the radius as the single parameter
and change the interface to demonstrate (refactoring see later):
172: function VolumeR(radius: double): double;
173: begin
174:
result:= 4/3*PI * Power(radius,2);
175: end;
Oops we got an incorrect result from the last function VolumeR() do you find it; glad to set an
assert before, otherwise it would be difficult to find that fault:
172: function VolumeR(radius: double): double;
173: begin
174:
result:= 4/3*PI * Power(radius,3);
175: end;
1
Note: radii are the plural of radius.
3
4. Yes the radius is r^3 so you see those magic words are more dirty than clean.
What about replace those numeric literals with an enumerator or a simple const:
172: function SphereVolume(radius: double): double;
173: begin
174:
result:= 4/CUBIC*PI * Power(radius,CUBIC);
175: end;
However once again, it is easier to use a calculator to test result and then set the assert ;-).
Beware of the float and round errors: the number Pi goes on forever!
It’s time to set some practice; you can test the source by yourself:
It can be down-loaded from http://www.softwareschule.ch/maxbox.htm (you’ll find the
download maxbox3.zip on the top left of the page). Once the download has finished, unzip the
file, making sure that you preserve the folder structure as it is. If you double-click maxbox3.exe
the box opens a default demo program2. Test it with F9 / F2 or press Compile and you should
hear a sound. So far so good now we’ll open the example:
421_PI_Power2.TXT
or direct as a file: http://www.softwareschule.ch/examples/421_PI_Power2.TXT
You find all info concerning run environment of the app and script in menu
/Program/Information/…
1.2 Magic Words
Clean Code means also to avoid string or numeric literals. Another solution to prevent hard coded
literals is a well known constant, an external file or the call of a user dialog. This is responsive
design at runtime. An indirect reference, such as a variable inside the program called ‘FileName’,
could be expanded by accessing a "select browse for file" dialog window, and the program code
would not have to be changed if the file moved.
Means also the user is responsible for the clean code he is in charge to set the right path and our
source is cleaned by user interaction.
The less we have to code the more we can set in advance or at runtime.
procedure GetMediaData(self: TObject);
begin
if PromptForFileName(selectFile, 'Media files (*.mp3)|*.mp3|*.mpg)|*.mpg', '',
'Select your mX3 media file Directory',
'D:kleiner2005download', False)
then begin
// Display this full file/path value
2
You don’t have to install maXbox or a script anyway, just unzip or copy the file
4
5. However it is advisable for programmers and developers not to fix the installation path of a
program or hard code some resources, since the default installation path is different in different
natural languages, and different computers may be configured differently. It is a common
assumption that all computers running Win have the primary hard disk labelled as drive C:, but
this is not the case.
You can also delegate some code to an external file. Which code or function objects are actually
used is specified through a configuration file or programmatically in a special-purpose
construction module. For example in maXbox: When you start the box a possible boot script is
loaded. Within the boot script to the IDE, you can perform common source control tasks, such as
file check in, check out, and of course change IDE settings and synchronization of your current
version. This is a script where you can put global settings and styles of the IDE, for example:
with maxForm1 do begin
caption:= caption +'Boot Loader Script maxbootscript.txt';
color:= clteal;
IntfNavigator1Click(self);
tbtnCompile.caption:= 'Compile!';
tbtnUsecase.caption:= 'UML UC';
maxform1.ShellStyle1Click(self);
memo2.font.size:= 16;
Info1Click(self);
end;
Writeln('BOOTSCRIPT ' +BOOTSCRIPT+ ' loaded')
When you delete the underscore in the filename to maxbootscript.txt the system performs
next time when you load maXbox and presents you with a different view. This boot script results
in the picture 2 below for example.
1: Configuration as external Cleaning
Try an example of OLE objects 318_excel_export3.TXT and the tutorial 19 as a purpose of
external files.
An external script or a least a second one could also be a test case to compare the behaviour.
5
6. Each test case and test project is reusable and rerun able, and can be automated through the
use of shell scripts or console commands.
Write also tests that have the potential to expose problems and then run them frequently, with
different external configurations or system configurations to load. If tests do fail, track down the
failure. Another point is the outsourcing of code; I do not mean we can outsource dirty code in an
external file, config files are just helpers to make it more clean and readable.
But don’t count on external tools. The function names have to stand alone, and they have
to be consistent in order for you to pick the correct method without any additional exploration.
In a code editor, type an object, class, structure or a pattern name followed by <Ctrl J> to
display the object. But it’s not a full code completion where you get after the dot (.) a list of types,
properties, methods, and events, if you are using the Delphi or C# languages.
Modern editing environments like Delphi XE, Eclipse or IntelliJ-provide context-sensitive clues,
such as the list of methods you can call on a given object. But note that the list doesn’t usually
give you comments you wrote around your function names and parameter lists. And again this is
against the first law that code has to be self explanatory.
You can’t count on an external tool; the source is the only substance!
And here comes the third and last law of clean code:
Don’t outsource dirty code.
It’s more a template copy of your building blocks. In the menu /Debug/Code Completion List
you get the defaults, here is an extract:
[cases | case statement | Borland.EditOptions.Pascal]
case | of
: ;
: ;
end;
[trye | try except | Borland.EditOptions.Pascal]
try
|
except
end;
My favour is: myform<Ctrl J> which represents or copies a form builder in your editor.
6
7. Useless to say that you can add your own templates to files. Many of the Code Editor
features are also available when editing HTML and CSS files. Code Completion (CTRL+J) and
syntax highlighting are available for HTML, XML and CSS files.
2: Test Application
Also a standard approach to break a running loop in a script or configuration is the well known
KeyPress or IsKeyPressed function you can test:
procedure LoopTest;
begin
Randomize;
REPEAT
Writeln(intToStr(Random(256*256)));
UNTIL isKeyPressed; //on memo2 output
if isKeypressed then writeln(Key has been pressed!');
end;
Clean Code doesn’t stop by source code as the third law states. Set also configuration as clean
you can but you know: convention over configuration.
The ini file format is still popular; many configuration files (such as Desktop or Persistence
settings file) are in this format. This format is especially useful in cross-platform applications,
where you can't always count on a system Registry for storing configuration information.
When you instantiate the TIniFile or TMemIniFile object, you pass the name of the ini file as
a parameter to the constructor. If the file does not exist, it is automatically created. You are then
free to read values using the various read methods, such as ReadString, ReadDate,
ReadInteger, or ReadBool.
This is how we read an ini file:
procedure getMaxBoxIniShort;
begin
with TIniFile.Create(ExePath+'maxboxdef.ini') do
try
except_conf:= ReadString('Form','EXCEPTIONLOG','');
ip_port:= ReadInteger('Web','IPPORT',0);
finally
7
8. writeln('inifile sysdata2: '+boot_conf+':'+intToStr(ip_port));
Free;
end;
end;
This process is handled directly, through an object so each time it changes timestamp of the file
also and not on demand.
Alternatively, if you want to read an entire section of the ini file, you can use the
ReadSection method. Similarly, you can write values using methods such as WriteBool,
WriteInteger, WriteDate, or WriteString.
Each of the Read routines takes three parameters. The first parameter (Form in our example)
identifies the section of the ini file. The second parameter identifies the value you want to read,
and the third is a default value in case the section or value doesn't exist in the ini file.
1.3 The Ever Technical Requirement
Most of our code is just too complicated driven by user requirements. Sometimes we are
uncertain about a low level detail because the requirements are unclear or technical driven.
Let me show you that by an example. First we have a simple routine to download a site:
begin
idHTTP:= TIdHTTP.Create(NIL)
try
memo2.lines.text:= idHTTP.get2('http://www.softwareschule.ch')
for i:= 1 to 10 do
memo2.lines.add(IntToStr(i)+' :'+memo2.lines[i])
finally
idHTTP.Free
end
Second:
Then the user wants to see the progress concerning download and wishes to save the file so
things get complicated in our code:
procedure GetFileDownloadProgress(myURL, myFile: string);
var HttpClient: TIdHttp;
aFileSize: Int64;
aBuffer: TMemoryStream;
begin
HttpClient:= TIdHttp.Create(NIL);
try
//HttpClient.Head('http://somewhere.ch/somefile.pdf');
HttpClient.Head(myURL);
aFileSize:= HttpClient.Response.ContentLength;
Writeln('FileSize of MemStream Download: '+inttoStr(aFileSize));
aBuffer:= TMemoryStream.Create;
try
while aBuffer.Size < aFileSize do begin
HttpClient.Request.ContentRangeStart:= aBuffer.Size;
if aBuffer.Size + RECV_BUFFER_SIZE < aFileSize then
HttpClient.Request.ContentRangeEnd:=
aBuffer.Size + RECV_BUFFER_SIZE - 1;
writeln('file progress: '+inttostr(aBuffer.size));
Application.ProcessMessages;
HttpClient.Get1(myURL, aBuffer); // wait until done
aBuffer.SaveToFile(Exepath+myFile);
end;
8
9. finally
aBuffer.Free;
end;
finally
HttpClient.Free;
end;
end;
As you can see it does almost the same (download a site) but it doesn’t look as clean as
before. We must use a buffer and low level stuff just to show the progress of the download.
At some level those details cannot be ignored or abstracted; they have to be specified. Such a
specification is code!
Let’s do the last step with some refactoring as a summary. Suppose you want to change the
parameter diameter to radius in our functions:
189:
190:
191:
192:
193:
194:
195:
196:
197:
198:
199:
200:
201:
202:
203:
204:
205:
206:
207:
208:
209:
210:
211:
212:
//Refactor to Radius ***************************************
function circleCircumR(radius: double): double;
begin
result:= 2*radius * PI;
end;
function circleAreaR(radius: double): double;
begin
//Area: r^2*PI
result:= Power(circleCircumR(radius)/PI/2,2) * PI;
end;
function SphereSurfaceR(radius: double): double;
begin
result:= 4*circleAreaR(radius);
end;
function SphereVolumeR(radius: double): double;
begin
result:= 4/CUBIC * circleAreaR(radius)*radius;
end;
//Refactor to Radius END***********************************
Assert(floatToStr(circleAreaR(1))=floatToStr(PI),'assert PI false');
1.4 Clean Code with Dirty Tricks
At the end some fun to do it. Under Include Files, list the files you want to include in a script. A
script can include a script from a file or from another unit. To include script from a file, use the
following code statement:
If its not find a valid file it says:
>>> Fault : Unable to find file '..maxbox3examples305_eliza_engined.INC'
used from 'E:maxboxmaxbox3maxbootscript_.txt'.
9
10. 305_indy_elizahttpserver.TXT
{$I ..maxbox3examples305_expo_engine.INC}
var i: int64;
for i:= 1 to 32 do //dirty
printF('Bin exponent with SHL: 2^%d = %d',[i, i SHL i DIV i]);
I hope you think about this code how it works. Most in clean code is about naming.
For instance some browsers favours “length” as a property in some javascript code – but mozilla
favours “size” and others name it sizeof().
Design an object with the four functions above of PI?
procedure TForm1_FormCreateShowRunDialog;
var piObj: TPIClass;
begin
piObj:= TPIClass.Create;
piObj.Precision:= F_Extended;
piObj.CircleArea(13.2);
//add more methods and properties
end;
Conclusion:
•
Code has to be self explanatory.
•
Functions should be small.
•
Don’t outsource dirty code.
As we all know, learning a new programming language or dialect is really not that hard, the hard
part is gaining a deeper understanding of the framework or API and memorizing the class names
and functions involved.
10197: //---------------------------------------------------------------------------10198: //**************mX4 Public Tools API *****************************************
10199: //----------------------------------------------------------------------------
//-----------------------------------------------------------------------------10702:
10703:
10704:
10705:
10706:
file : unit uPSI_fMain.pas; OTAP Open Tools API Catalog
// Those functions concern the editor and pre-processor, all of the IDE
Example: Call it with maxform1.Info1Click(self)
Note: Call all Methods with maxForm1., e.g.:
maxForm1.ShellStyle1Click(self);
10
11.
Feedback: max@kleiner.com
Links of maXbox and Code:
http://www.softwareschule.ch/maxbox.htm
http://sourceforge.net/projects/maxbox
http://sourceforge.net/apps/mediawiki/maxbox/
http://www.softwareschule.ch/examples/421_PI_Power2.TXT
http://www.softwareschule.ch/download/maxbox_starter24.pdf
11
12. 1.5 Appendix
EXAMPLE: List Objects
Working with Lists
The VCL/RTL includes many classes that represents lists or collections of items. They vary depending
on the types
of items they contain, what operations they support, and whether they are persistent.
The following table lists various list classes, and indicates the types of items they contain:
Object Maintains
TList A list of pointers
TThreadList A thread-safe list of pointers
TBucketList A hashed list of pointers
TObjectBucketList A hashed list of object instances
TObjectList A memory-managed list of object instances
TComponentList A memory-managed list of components (that is, instances of classes descended from
TComponent)
TClassList A list of class references
TInterfaceList A list of interface pointers.
TQueue A first-in first-out list of pointers
TStack A last-in first-out list of pointers
TObjectQueue A first-in first-out list of objects
TObjectStack A last-in first-out list of objects
TCollection Base class for many specialized classes of typed items.
TStringList A list of strings
THashedStringList A list of strings with the form Name=Value, hashed for performance.
The ProgID for each of the Shell objects is shown in the following table.
Object
TList
TThreadList
TBucketList
TObjectBucketList
TObjectList
TComponentList
TClassList
TInterfaceList
TQueue
TStack
TObjectQueue
TObjectStack
TCollection
TStringList
THashedStringList
Function
A list of pointers
A thread-safe list of pointers
A hashed list of pointers
A hashed list of object instances
A memory-managed list of object instances
A memory-managed list of components
A list of class references
A list of interface pointers
A first-in first-out list of pointers
A last-in first-out list of pointers
A first-in first-out list of objects
A last-in first-out list of objects
Base class for many specialized classes of typed items
A list of strings
A list of strings with the form Name=Value, hashed for performance.
12