Control structures allow programmers to control the flow of execution of code in R. This document discusses various control structures like if-else loops, for loops, while loops, and functions. It also covers various data types in R like vectors, lists, data frames, factors and how to handle vectors through operations like addition, indexing, etc. It provides examples for each concept discussed.

1. Prof. Neeraj Bhargava
Pramod Singh Rathore
Department of Computer Science
School of Engineering & System Sciences,
MDS University Ajmer, Rajasthan, India
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Control Structures in R

2. Control
Structures
 If…else loop
 For loop
 While loop
 Functions
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3. If….else loop
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If…else loop works on conditions
It will always s evaluate something and return a logical output, based on this a
set of codes will be executed.

4. For loop
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When you want to iterate over a range of values or series of numbers names
we use fro loop.
Most of the time we use for loops only
We need to store each value mentioned in a range in a variable
for(i in 1:1000) {
print(i)
}

5. While loop
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While loop and for loop are almost same
1. i=1
2. while(i<100){
3. print(i)
4. i=i+1
5. }

6. Functions
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A function is a set of statemnts organized together to perform a specific task
R function is created by using a deywork
‘function’
Function_name=function(arg1,arg2…..){
Function body
}

7. If…else
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data(“iris”)
View(iris) inbuilt dataset
str(iris)
#mean,median,standard deviation
Desc_setosa=matrix(nrow=5,ncol=4,
dimnames=list(c(“mean”,”median”,”mode”,”standard deviation”,”no
ofcases”),colnames(iris)[1:4]))

8. Lists
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List is similar as vector
It is a data structure have components of mixed data types

9. Data frames
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A data frame is used fro storing data tables
It is a special case of list which as each components of equal length
Each component form the column and contents of the components form the
rows
Data frame can be define by data.frame() function

10. Factors
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Factor is a data structure used for fields that takes only predefined, finite
number of values (catergorialc data)
Factor variable will always have levels
While using data.frame() all the character data are converted into factor

11. How to handle vector in R
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c(2,3,4) output : 2 3 4
Class(c(2,3,4)) numeric
C(2,3,”pramod”) “2” “3” “pramod”
class(C(2,3,”pramod”)) character
Length(c(2,3,4)) 3
a = c(2,3,4)
b= c(“a”,”b”,”c”)
vec=c(a,b) “2”,”3”,”4”,”a”,”b”,”c”
class(vec) character
Class(a) numeric

12. How to handle vector in R
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A= c(1,2,3,4)
b= c(-1,-2,-3,-4)
Vect=a+b 0 0 0 0
v1=c(1,2,3)
v2=c(4,5,6,7)
v3=v1+v2 warning message
5 7 9 8 recycling rule

13. How to handle vector in R
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v4= c(1:10)
v4[5] 5
V4[-5] 1 2 3 4 6 7 8 9 10
V4(3:5) 3 4 5
V4[c(3:5),10] 3 4 5 10 range indexing

14. Assignment 1
 What is data types in R?
 Explain each data type with suitable example
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15. Queries ????
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