Displaying 1 result from an estimated 1 matches for "item_position".
2006 Apr 13
1
Subset rows over multiple columns
...and righta_b and then I could then use tapply and get what I need
without any subsetting. That is
testScores <- reshape(tt, idvar='id', varying=list(c('itd_1', 'itd_45'),
c('righta_a', 'righta_b')), v.names=c('item','answer'),
timevar='item_position', direction='long')
with(testScores, tapply(answer, item, mean))
Or I could get
with(testScores, tapply(answer, list(item, position), mean))
The only problem here is that I have some duplicate IDs in the data and
reshape doesn't like turning data on its head in that situation, s...