Nested If Else Statement - Argument "Yes" Missing with No Default

Question

Basically I have a column with signal strength values (Sig_1) and am making a new column called "Activity2". If the difference between one value and the next (of Sig_1) is equal to or more than 5, I would like an "A" to appear in my new column. If the signal strength is below -130, I would like a "W" to appear and if it is above -130 then I would like an "I".

I have a nested ifelse statement:

df <- transform(df, Activity2 = c(0, ifelse(diff(Sig_1)<5), 
ifelse(Sig_1<-130), "W", "I"), "A")

I can't see what's wrong with it but I keep getting:

"Error in ifelse(diff(Sig_1) < 5) :
argument "yes" is missing, with no default"

brackets in the wrong place... c(0, ifelse(diff(Sig_1)<5, ifelse(Sig_1<-130, "W", "I"), "A")) — Troy, Jan 20 '14 at 10:10
have a look at the answer to this question: [link](http://stackoverflow.com/questions/18012222/nested-ifelse-statement-in-r) — thijs van den bergh, Jan 20 '14 at 10:10

score 4 · Answer 1 · answered Jan 20 '14 at 10:17

The error is due to wrong brackets: You basically have ifelse(TRUE). Also be careful with the difference between a <- 1 and a < -1. Here's some code that should do what you want:

df <- transform(df, Activity2 = 
ifelse(c(0, diff(Sig_1))<5, ifelse(Sig_1 < -130, "W", "I"), "A"))

Nested If Else Statement - Argument "Yes" Missing with No Default

1 Answers1