Writing an Indicator function in R

Question

I am trying to create an indictor variable, Z, in R, i.e If I have some event A, I want Z to give a result of 1 if A is true and 0 if A is false. I have tried this:

Z=0
if(A==(d>=5 && d<=10))
  {
    Z=1
  }
  else
  {
    Z=0
  }

But this doesn't work. I was also thinking i could try to write a separate function called indicator:

indicator = function()

Any suggestions would be really helpful, thank you

Possible duplicate of [Indikator function in R](http://stackoverflow.com/questions/20096514/indikator-function-in-r) — Waldir Leoncio, Mar 03 '16 at 11:12

score 3 · Answer 1 · answered Mar 19 '14 at 17:57

3

You could easily write something like this

indicator<-function(condition) ifelse(condition,1,0)

ifelse can be used on vectors, but it works perfectly fine on single logical values (TRUE or FALSE).

answered Mar 19 '14 at 17:57

Max Candocia

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Thank you, that was a lot of help! – user3438924 Mar 19 '14 at 18:41
2

Also 1*(condition) can do the same thing, and it's shorter (although a bit harder to read). – Max Candocia Dec 06 '14 at 04:42

score 2 · Answer 2 · edited Apr 24 '14 at 23:15

2

Booleans FALSE / TRUE can be coerced to be 0 or 1 and then be multiplied:

Indicator<-function(x, min=0, max=Inf)
    { 
        as.numeric(x >= min) * as.numeric(x <= max)
    }

edited Apr 24 '14 at 23:15

falsarella

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answered Apr 24 '14 at 22:47

Marcelo Befumo

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1

score 0 · Answer 3 · answered Sep 21 '18 at 13:21

0

You can use

a <- data.frame(a = -5:5, b = 1:11) indicator <- function(data) I(data > 0) + 1 - 1 indicator(a)

a can be vector, data frame...

And you can chance the logical in I function with your interest.

answered Sep 21 '18 at 13:21

Rogério Boff

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1

score -1 · Answer 4 · edited May 23 '17 at 11:50

-1

There is no need to define A, just test the condition. Also, remember that && and & have different uses in R (see R - boolean operators && and || for more details), so maybe that is part of your problem.

if (d>=5 & d<=10)
   {
   Z <- 1
   }
  else
   {
   Z <- 0
   }

Or, as suggested in the other answer use ifelse:

z <- ifelse((d>=5 & d<=10), 1, 0)

edited May 23 '17 at 11:50

Community

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1

answered Mar 19 '14 at 18:02

nico

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Writing an Indicator function in R

4 Answers4