I'm learning R and am converting some code from SPSS into R. My background
is in SAS/SPSS so the vectorization is new to me and I'm trying to learn
how to NOT use loops...or use them sparingly. I'm wondering what the
most efficient to tackle a problem I'm working on is. Below is an example
piece of code. Essentially what it does is set a variable to zero, loop
through item responses, and add one if a condition is met. For example, if
item one was responded as a 1 then add one to the final variable. If item
two was responded as a 2 then add one to the final variable. I have to do
this for five scales with each scale having 6 items half of which may have
the 1 response pattern and half the 2 pattern.
Any suggestions on how best to tackle this in R would be helpful.
Craig
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Old SPSS code sample
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Compute Variable = 0.
IF (item1 = 1) Variable = Variable +1 .
IF (item2= 2) Variable = Variable +1 .
IF (item3 = 1) Variable = Variable +1.
IF (item4 = 2) Variable = Variable +1.
EXECUTE .
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