reshapeConvertToLong.R

library(reshape2)

# existing data df.tmp like:
#   ldl.begin group end.ldl.1  end.ldl.2  end.ldl.3  end.ldl.4
# 1     <=3.4   ctl 0.6923077 0.30769231 0.00000000 0.00000000
# 2   3.4-4.1   ctl 0.2622951 0.49180328 0.21311475 0.03278689
# 3   4.1-4.9   ctl 0.0000000 0.28571429 0.57142857 0.14285714

# convert to long
melt(df.tmp, id.vars=c("ldl.begin", "group"))

# looks like:
#   ldl.begin group  variable      value
# 1      <=3.4   ctl end.ldl.1 0.69230769
# 2    3.4-4.1   ctl end.ldl.1 0.26229508
# 3    4.1-4.9   ctl end.ldl.1 0.00000000
# 4       >4.9   ctl end.ldl.1 0.00000000
# 5      <=3.4   trt end.ldl.1 0.77777778
# etc ...