Contrasts(LETTERS[1:5])
#   B-A C-A D-A E-A C-B D-B E-B D-C E-C E-D
# A  -1  -1  -1  -1   0   0   0   0   0   0
# B   1   0   0   0  -1  -1  -1   0   0   0
# C   0   1   0   0   1   0   0  -1  -1   0
# D   0   0   1   0   0   1   0   1   0  -1
# E   0   0   0   1   0   0   1   0   1   1
Run the code above in your browser using DataLab