This document provides basic guidelines for MATLAB programming. It includes: - An overview of the MATLAB window and commonly used commands like disp, fprintf, clear, clc. - Examples of how to perform matrix calculations directly in the command window like matrix multiplication, element-wise multiplication, and operations on vectors. - How to define 1D and 2D arrays using for loops and take input from the user. - An introduction to function handlers using the @ symbol and an example of finding the roots of a transcendental equation. - A brief discussion of plotting multiple curves using subplots and reading data from an Excel file. - Suggestions for making your own functions,

1. Basic Guidelines for MATLAB Programming
By
RANJAN PAL
Ph.D. Research Scholar
IIT Kharagpur
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2. 2
MATLAB window
(1) Directory where you save your files
(2) Script file(3) Saved
files in your
current
directory
(4) MATLAB Workspace
(5) Command window

3. Commonly used commands
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Command Name Usage
disp displays message in command window
fprintf Prints the i/o msg in command window
n takes you to next line
t acts like a space bar
clc clears command window
clear all clears all the data stored in workspace
%’some txt msg’ its for user information
In the beginning of every code, when you define a function, remember that
the name of function and the name that you save for .m file should be same

4. 4
Matrix Calculations in COMMAND window
Write nos. from 1 to 10 >> H=1:10
Let M=[1 2; 3 4] and N=[4 5 ;6 7],
Matrix Multiplication >> R=M*N
Element wise multiplication >> S=M.*N
Let A=[4 5 6] and B=[7 8 9] i.e. two vectors
Dot product is given by, >> C=dot(A,B)
Cross Product is given by, >> D=cross(A,B)
Create 4*4 identity matix >> eye(4)
3*2 matrix, all elements are 1 >> ones(3,2)
3*2 matrix, all elements are 0 >> zeros(3,2)
Operations Write these in COMMAND window
Define matrix >> A=[1 2 3;4 5 6; 7 8 9]
Transpose of A >>B=A'
All elements of 2nd column of matrix A >> C=A(:,2)
All elements of 2nd row of matrix A >> D=A(2,:)
Size of matrix A >> E=size(A)
1st & 2nd row and 2nd & 3rd column >> F=A(1:2,2:3)
Extract A13 element of matrix A >> G=A(1,3)

5. Define 1D array (Matrix of 1*n)
clear all;
clc;
% No of rows by default is 1 i.e m=1
% matrix is of the form : a1j
n=input('Enter the column size of array:n ')
a=1:n % a is matrix of size : 1*n
disp('Enter the elements of matrix:a ')
for j=1:n
a(1,j)=input('') % if a=1*n matrix ,then a11 a12 a13 ...........a 1n
end
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Write this programme as a ‘SCRIPT’ file and save with ‘.m’ extension
Enter ‘F5’ to run the programme

6. clear all;
clc;
m=input('Enter the row size of array:m ')
n=input('Enter the column size of array:n ')
a=[m;n] % a is Matrix of size a(m*n)
disp('Enter the elements of matrix :a ')
for i=1:m
for j=1:n
a(i,j)=input('') % if a=2*3 matrix ,then a11 a12 a13 then a21 a22 a23
end
end
disp(a)
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Write this programme as a ‘SCRIPT’ file and save with ‘.m’ extension
Enter ‘F5’ to run the programme
Define 2D array (Matrix of m*n)

7. Basics of function handlers
• Lets say we have f=x+y, And we need to find f(4,5)
• In matlab, to achieve this ,we make use of function handlers
• In matlab command window, write this:
>>f = @(x,y) (x+y); % Press enter
>>F=f(4,5) % Press enter
(*You get the desired value i.e. 9*)
(*Observe what happens when you remove the (;) symbol *)
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8. Obtaining the roots of Transcendental Eq
by function handling ‘@(x)’
when you know approximately where the root lies
We define a function as follows:
>> f = @(x) cos(x) * cosh(x) + 1 ; % cos(x)*cosh(x)+1=0
>> fzero(f,2)
ans =
1.8751
 This is just to tell you that MATLAB has many inbuilt functions to solve a given
problem like roots of equations, ode etc.
 You can explore them for you interest
 But not to be used in exams 8

9. Plot more than 1 curve: ‘Sub-Plot’
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Write this programme as a ‘SCRIPT’ file and save with ‘.m’ extension
Enter ‘F5’ to run the programme

10. • Prepare this excel file that contains two sheets
• Save this file with the name ‘Square Cube.xlsx’
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Read From Excel File - 1
Sheet 1 ‘Square’ Sheet 2: ‘cube’

11. Read From Excel File - 2
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Write this programme as a ‘SCRIPT’ file and save with ‘.m’ extension
Enter ‘F5’ to run the programme

12. Making your function
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13. PROBLEM SUM
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14. Make your own function
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15. GET INPUT VALUES FROM THE USER
and CALL the user defined function
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16. To run the programme, you can follow any one of the below mentioned steps:
1) press F5 in MATLAB editor, after you have saved the ‘Run_this_code.m’ file
2) click the ‘Run’ option in MATLAB editor
Run the Programme
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17. O/P of Euler Cauchy for ODE
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18. Points to Remember
• This PPT is to give you basic idea about MATLAB programming, it
doesn't teach you MATLAB thoroughly.
• You need to explore it more yourself.
• You can take help of https://www.mathworks.com/ for syntax and
learn new commands
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