CODEWITHSUNDEEP
rmultiple-columnsdummy-variable
user9563072
user9563072

Reputation:

Create dummy-column based on another columns

Let's say I have this dataset

> example <- data.frame(a = 1:10, b = 10:1, c = 1:5 )

I want to create a new variable d. I want in d the value 1 when at least in of the variables a b c the value 1 2 or 3 is present. d should look like this:

d <- c(1, 1, 1, 0, 0, 1, 1, 1, 1, 1)

Thanks in advance.

Upvotes: 2

Views: 1958

Answers (7)

PKumar
PKumar

Reputation: 11128

You can do this using apply(although little slow)

Logic: any will compare if there is any 1,2 or 3 is present or not, apply is used to iterate this logic on each of the rows. Then finally converting the boolean outcome to numeric by adding +0 (You may choose as.numeric here in case you want to be more expressive)

d <- apply(example,1 ,function(x)any(x==1|x==2|x==3))+0

In case someone wants to restrict the columns or want to run the logic on some columns, then one can do this also:

d <- apply(example[,c("a","b","c")], 1, function(x)any(x==1|x==2|x==3))+0

Here you have control on columns on which one to take or ignore basis your needs.

Output:

> d
 [1] 1 1 1 0 0 1 1 1 1 1

Upvotes: 1

Jaap
Jaap

Reputation: 83215

Two other possibilities which work with any number of columns:

#option 1
example$d <- +(rowSums(sapply(example, `%in%`, 1:3)) > 0)

#option 2
library(matrixStats)
example$d <- rowMaxs(+(sapply(example, `%in%`, 1:3)))

which both give:

> example
    a  b c d
1   1 10 1 1
2   2  9 2 1
3   3  8 3 1
4   4  7 4 0
5   5  6 5 0
6   6  5 1 1
7   7  4 2 1
8   8  3 3 1
9   9  2 4 1
10 10  1 5 1

Upvotes: 1

Andre Elrico
Andre Elrico

Reputation: 11480

general solution:

example %>%
sapply(function(i)i %in% x) %>% apply(1,any) %>% as.integer
#[1] 1 1 1 0 0 1 1 1 1 1

Upvotes: 0

hpesoj626
hpesoj626

Reputation: 3619

With the dplyr package:

library(dplyr)
x <- 1:3
example %>% mutate(d = as.integer(a %in% x | b %in% x | c %in% x))

Upvotes: 1

r.user.05apr
r.user.05apr

Reputation: 5456

Will work for any number of vars:

example <- data.frame(a = 1:10, b = 10:1, c = 1:5 )
x <- c(1, 2, 3)
as.integer(Reduce(function(a, b) (a %in% x) | (b %in% x), example))

Upvotes: 1

Terru_theTerror
Terru_theTerror

Reputation: 5017

Try this method, verify if in any column there is at list one element present in x.

x<-c(1,2,3)
example$d<-as.numeric(example$a %in% x | example$b %in% x | example$c %in% x)
example
    a  b c d
1   1 10 1 1
2   2  9 2 1
3   3  8 3 1
4   4  7 4 0
5   5  6 5 0
6   6  5 1 1
7   7  4 2 1
8   8  3 3 1
9   9  2 4 1
10 10  1 5 1

Upvotes: -1

Sotos
Sotos

Reputation: 51582

You can use rowSums to get a logical vector of 1, 2 or 3 appearing in each row and wrap it in as.integer to convert to 0 and 1, i.e.

as.integer(rowSums(df == 1|df == 2| df == 3) > 0)
#[1] 1 1 1 0 0 1 1 1 1 1

Upvotes: 2

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