Hi everyone, I met a difficulty. The following data are fluxes' value of N2O emission, I want to calculate the average value of data in second column grouped by column one, because there are thousands of values for N2O-1 and N2O-2,N2O-3,N2O-4...... You know I am just a Perl newby, so can you show me the Perl code to solve the problem? DATA:

N2O-1 0.02
N2O-1 0.47
N2O-1 0.22
N2O-2 0.02
N2O-2 5.87
N2O-2 7.32
N2O-3 3.45
N2O-3 1.81
N2O-3 2.36
N2O-3 4.70
N2O-4 9.60
N2O-4 4.95
N2O-4 6.99
[download]

The result of the calculation should be following data:

N2O-1 0.297
N2O-2 4.403
N2O-3 2.54
N2O-4 7.18
[download]

I realy appreciated for your help! Thanks for your attention!