[R] deleting rows provisionally

[Hans Ekbrand]

On Fri, Apr 24, 2009 at 04:50:48AM -0700, onyourmark wrote:
> 
> Hi. Thanks very much for the reply and the good suggestion. It works well.
> But I don't get why the for loop is not deleting anything or making any
> assignments? Or I should say, doesn't answer3[-i,] delete entries from
> answer3 when the if condition is true?

Your for loop was:

for(i in 1:1537){if(answer2[i,1]==answer2[i,2]){answer3[-i,]}}

No, answer3[-i] does not remove item i from answer3, it returns an
anonymous temporary object which is identical to (answer3 without item
i). Since that object not saved, it is deleted when the loop enters
the next iteration. To actually *modify* answer3 you can use:

answer3 <- answer3[-i]

-- 
Hans Ekbrand (http://sociologi.cjb.net) <hans at sociologi.cjb.net>
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