CODEWITHSUNDEEP
r
Emeline
Emeline

Reputation: 171

R - Creating a new variable using same condition on many variables

I am quite a beginner in R and I am stuck with this problem:

I have a dataset (data) of 24 columns. Each column is an answer to a question : "Is your xxx hurting"? xxx varies in each column (it can be back, head...) Each column can take 3 values: 1 if it does not hurt, 2 if it hurts a bit, 3 if it pains.

I want to create a new variable (fragile) to count each time a person said it hurted a bit somewhere.

data$fragile <- ifelse(data$var1 ==2 , 1, 0) + ifelse(data$var2 == 2, 1, 0) + ...

But it is quite long so I would like to not do it

I tried doing a loop but I read somewhere that R is not made to do loops (and my loop does not work anyway)

data$fragile <-  for(i in dataset[1:24]){ifelse(i == 2, 1, 0)}

And when I do head(data$fragile), "NULL" appears...

What should I do?

I am sure this question has already been asked several times but I do not find the right keywords.

Upvotes: 0

Views: 215

Answers (2)

Ronak Shah
Ronak Shah

Reputation: 389265

You can use rowSums : 

data$fragile <- +(rowSums(data == 2) > 0)

This will give 1 to fragile column if there is 2 in any of the column for a particular row.

In the new dplyr 1.0.0 we can use rowwise with cur_data().

library(dplyr)
data %>% rowwise() %>% mutate(fragile = +(any(cur_data() == 2)))

Upvotes: 1

Jan
Jan

Reputation: 5274

Given the assumption that you columns of interest have the indices 1:24:

data$fragile <- apply( data[1:24], 1, function(x) sum(x==2, na.rm = TRUE) )

If you have the columns in a different order just change the index.

This solution, however, is quite slow compared to rowSums.

Upvotes: 1

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