I have a table of survey questions:
ques <- data.frame(stringsAsFactors=F,
question_id=c("q1","q2"),
question_nm=c("computer_hrs","exercise_hrs"),
question_txt=c("How many hours did you spend last week on a computer?",
"How many hours did you spend last week on exercise?")
)
The question_nm is a short description string, already checked to be valid as a variable name.
I have a table of responses:
resp <- data.frame(stringsAsFactors=F,
respondent_id=c(1,2),
respondent_nm=c("Joe Programmer","Jill Athlete"),
q2=c(1,100), #column order in resp not guaranteed same as row order in ques
q1=c(100,1)
)
In order to have meaningful response variable names I wish to replace the names q1 and q2 with computer_hrs and exercise_hrs.
Note that you would get the wrong answer with:
names(resp)[ques$question_id %in% names(resp)] <- ques$question_nm #wrong
due to the column order in responses not matching the row order in questions. (I know I could fix that by sorting each order.)
I can do this with a for loop...
for (q in ques$question_id){
names(resp)[names(resp)==q] <- ques$question_nm[ques$question_id==q]
}
... but given a function that returned the mapping of the elements of ques$question_id to names(resp), similar to %in% but returning the position rather than T/F, I could do it without the For loop. Unfortunately, the only way I know to write that function involves a For loop.
Is there a way to accomplish this replacement without the loop?
