On 2011-06-04 11:11, Peter Ehlers wrote:
On 2011-06-03 13:34, Jason024 wrote:
I have a data frame like this:
col1 col2
r1 2 1
r2 4 3
r3 6 5
r4 8 7
r5 10 9
r6 12 11
r7 14 13
r8 16 15
r9 18 17
r10 20 19
I want to modify this data frame, for example, assign every row in column
col1 and col2 to -1 if the values in col1 is less than 12 and values in col2
is greater than 10. The result should look like this:
col1 col2
r1 -1 1
r2 -1 3
r3 -1 5
r4 -1 7
r5 -1 9
r6 12 -1
r7 14 -1
r8 16 -1
r9 18 -1
r10 20 -1
I have been struggling to make it to work. Any help is appreciated!
This seems made for within(); calling your data.frame 'd':
d.new<- within(d, {
col1<- ifelse(col1< 12, -1, col1)
col2<- ifelse(col2> 10, -1, col2)
})
And, of course, the ifelse() isn't necessary:
d.new <- within(d, {
col1[ col1 < 12 ] <- -1
col2[ col2 > 10 ] <- -1
})
Peter Ehlers
Jason
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and provide commented, minimal, self-contained, reproducible code.
______________________________________________
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
