> On 10 Aug 2017, at 06:54, Courtney Benjamin <cbenj...@btboces.org> wrote:
>
> 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
I could not follow the question up clearly. But one thing that come across to
my sight is that you have values in elsq2wbl$EVERRELJOB as below:
summary(factor(elsq2wbl$EVERRELJOB))
-9 -8 -7 -4 -3 0 1
139 459 946 2488 1948 4619 5598
and in fact, you want to set negative values to NA.
> ##Recoding Negative Responses to NA
> elsq2wbl [elsq2wbl[, "EVERRELJOB"] < -3, "EVERRELJOB"] <- NA
But after the command, you still have 1948 ‘-3' in the variable;
summary(factor(elsq2wbl$EVERRELJOB))
-3 0 1 NA's
1948 4619 5598 4032
So I think, you need to fix the line as follows:
> ##Recoding Negative Responses to NA
> elsq2wbl [elsq2wbl[, "EVERRELJOB"] <= -3, "EVERRELJOB"] <- NA
Instead of using ‘-2' and ‘-3' as threshold to set NA for different variables,
why don’t you use “less than zero” condition as follows?
elsq2wbl [elsq2wbl[, "EVERRELJOB"] < 0, "EVERRELJOB"] <- NA
elsq2wbl [elsq2wbl[, "PSWBL"] < 0, "PSWBL"] <- NA
Hence, in both columns (variables), values lower than zero will be NA and you
only will have 0, 1 and NA values in the variable as you called “binary”.
_ifelse_ part:
You have NA’s in both variables. In this circumstances, consider following
ifelse samples (both sides of '&' can be exchanged)
ifelse(TRUE & TRUE, 1, 0) # 1
ifelse(TRUE & FALSE, 1, 0) # 0
ifelse(FALSE & FALSE, 1, 0) # 0
ifelse(TRUE & NA, 1, 0) # NA
ifelse(FALSE & NA, 1, 0) # 0
according to above, try to create new logic to achieve what you need.
In your last neste-ifelse, you forgot to define a value if deepest ifelse
statement fails.
elsq2wbl$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, "Forgotten value")))
Also, please, try to create a _minimal reproducible example_ instead of make us
download a big csv file (219 columns x 16197 rows) and try to understand what
you are trying to do. :)
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