[R] Creating New Variable Using Ifelse

[Courtney Benjamin]

Hello R Help List,

I am an R novice and trying to use the ifelse function to create a new binary variable based off of the responses of two other binary variables; NAs are involved.  I pulled it off almost successfully, but when I checked the counts of my new variable for accuracy, I found that a small portion of the NA cases were not being passed through as NAs, but as "0" counts in my new variable.  My many attempts at creating a nested ifelse statement that would pass the NAs through properly have not been successful.  Any help is greatly appreciated.

Here is a MRE:?

library(RCurl)
data <- getURL("https://raw.githubusercontent.com/cbenjamin1821/careertech-ed/master/elsq2wbl.csv")
elsq2wbl <- read.csv(text = data)

##Recoding Negative Responses to NA
elsq2wbl [elsq2wbl[, "EVERRELJOB"] < -3, "EVERRELJOB"] <- NA
elsq2wbl [elsq2wbl[, "PSWBL"] < -2, "PSWBL"] <- NA

#Labeling categorical variable levels
elsq2wbl$EVERRELJOB <- factor(elsq2wbl$EVERRELJOB, levels = c(0,1), labels = c("No","Yes"))
elsq2wbl$PSWBL <- factor(elsq2wbl$PSWBL, levels = c(0,1), labels = c("No","Yes"))

##Trying to create a new variable to indicate if the student had a job
#related to the college studies that was NOT a WBL experience
elsq2wbl$NONWBLRELJOB <- ifelse(elsq2wbl$PSWBL=="No" & elsq2wbl$EVERRELJOB=="Yes",1,0)

#Cross tab to check counts of two variables that new variable is based upon
xtabs(~PSWBL+EVERRELJOB,subset(elsq2wbl,BYSCTRL==1&G10COHRT==1),addNA=TRUE)

#Checking count of newly created variable
Q2sub <- subset(elsq2wbl,BYSCTRL==1&G10COHRT==1)
library(plyr)
count(Q2sub,'NONWBLRELJOB')

#The new variable has the correct count of "1", but 88 cases too many for "0"
#The cross tab shows 20 and 68 NA cases that are being incorrectly counted as "0" in the new variable

#My other approach at trying to handle the NAs properly-returns an error
elsq2wbl$NONWBLRELJOB <- ifelse(elsq2wbl$PSWBL=="No" & elsq2wbl$EVERRELJOB=="Yes",1,ifelse(is.na(elsq2wbl$PSWBL)&is.na(elsq2wbl$EVERRELJOB),NA,
                                                                                           ifelse(elsq2wbl$PSWBL!="No" & elsq2wbl$EVERRELJOB!="Yes",0)))



Courtney Benjamin

Broome-Tioga BOCES

Automotive Technology II Teacher

Located at Gault Toyota

Doctoral Candidate-Educational Theory & Practice

State University of New York at Binghamton

cbenjami at btboces.org<mailto:cbenjami at btboces.org>

607-763-8633

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