Reshaping from long to wide with some missing data (NA's) on time invariant variables

Question

When using stats:::reshape() from base to convert data from long to wide format, for any variables designated as time invariant, reshape just takes

Answer 1

I don't know how to fix the problem but one way to fix the symptom would be to push the NA values down in the order.

testdata <- testdata[order(testdata$timeinvariant),]
testdata
#  id process1 timeinvariant time
#3  2      3.5             4    1
#2  1      4.0             6    2
#1  1      3.0            NA    1
reshaped<-reshape(testdata,v.names="process1",direction="wide")
reshaped
#  id timeinvariant process1.1 process1.2
#3  2             4        3.5         NA
#2  1             6        3.0          4

A more general solution will be to make sure there is only one value in the timevariant column per id

testdata$timeinvariant <- apply(testdata,1,function(x) max(testdata[testdata$id == x[1],"timeinvariant"],na.rm=T))
testdata
#  id process1 timeinvariant time
#3  2      3.5             4    1
#2  1      4.0             6    2
#1  1      3.0             6    1

This can be repeated for any number of columns before calling the reshape function. Hope this helps