Reshape long to wide with multiple groupings

Question

My data looks like this:

  Smoker PtNo Day Hour FEV1 timename
1       0    1   1    0 3.26     d1h0
2       0    1   1    2 3.05     d1h2
3       0    1   1    4         


        

Answer 1

Are you looking for this?

reshape(dat,direction='wide',
        idvar=c('Smoker','PtNo'),
        v.names='FEV1',
        timevar='timename',
        drop=c('Day','Hour'))

 Smoker PtNo FEV1.d1h0 FEV1.d1h2 FEV1.d1h4 FEV1.d1h6 FEV1.d2h0 FEV1.d2h2 FEV1.d2h4 FEV1.d2h6 FEV1.d3h0 FEV1.d3h2
1      0    1      3.26      3.05      3.02      3.27      3.28      3.07      3.35      3.07      3.28      3.44