CODEWITHSUNDEEP
r
Shaun
Shaun

Reputation: 949

Modifying string with a condition

I want to change specific names within a list, using a condition

Here is the list of string items

varnames <- c("var1_L1","var2_L1","var3_L1",  "var4_L1",  "Coefs_L1", "Pval_L1")

I would like to remove everything to the right of "_" but only for items that have "var" in the text

This will remove everything for all items

sub("_.*","", varnames)

I've tried to use an if condition with this but couldn't get it to work.

If it helps, this would be what the end result looks like

varnames_result <- c("var1","var2","var3", "var4",  "Coefs_L1", "Pval_L1")

Any help greatly appreciated. Thanks

Upvotes: 0

Views: 22

Answers (2)

Ronak Shah
Ronak Shah

Reputation: 388982

You can use posiitve lookbehind regex to remove everything that follows 'var' + number.

sub('(?<=var\\d).*', '', varnames, perl = TRUE)
#[1] "var1"     "var2"     "var3"     "var4"     "Coefs_L1" "Pval_L1"

Upvotes: 1

Onyambu
Onyambu

Reputation: 79228

You could do:

 sub("(var.*?)_.*", "\\1", varnames)
[1] "var1"     "var2"     "var3"     "var4"     "Coefs_L1" "Pval_L1"

If there is only one _ then (var.*)_.* is sufficient

Upvotes: 2

Related Questions