Using if else statement for multiple conditions

Question

Sample data:

x<-runif(100, min=0, max=1)
y<-runif(100, min=0, max=1)
dif<-x-y
dat<-data.frame(x,dif)

What I want to do is to create another column in data frame dat called suit. If x is less than 0.15 and dif is less than 0, than suit should have a value of 3. If x is less than 0.15 and dif is greater than 0, than suit should have a value of 2 and if dif is greater than 0, than suit has value of 1.

This is the code that I am prepared.

if(dat$x<0.15 & dat$dif<0){
   dat$suit<-3
} else {
if(dat$x>=0.15 & dat$dif<0){
   dat$suit<-2  
} else {
  dat$suit<-1  
 }
}

It gives all the values of dat$suit as 1. I am not sure what I am doing wrong here.

Thank you for your help.

akrun · Accepted Answer · 2016-04-23 15:32:56Z

11

This can be done using either ifelse

with(dat, ifelse(x < 0.15 & dif <0, 3, ifelse(x > 0.15 & dif < 0, 2, 1)))

Or

with(dat, as.numeric(factor(1+4*(x < 0.15 & dif < 0) + 2*(x>=0.15 & dif < 0))))

answered Apr 23, 2016 at 15:32

akrun

891k38 gold badges590 silver badges700 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Matthew Lundberg · Accepted Answer · 2016-04-23 15:37:46Z

5

The problem with your statement is that if only checks the first element of the expression tested -- you should have received a warning. ifelse is vectorized.

In addition, you can perform the tests in the reverse order for a simpler, equivalent expression:

with(dat,
     ifelse(dif >= 0 , 1 , ifelse(x < 0.15, 3, 2))
)

answered Apr 23, 2016 at 15:37

Matthew Lundberg

42.8k6 gold badges93 silver badges112 bronze badges

Collectives™ on Stack Overflow

Using if else statement for multiple conditions

2 Answers 2

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related