sfhist2 (2.0-git)
Compute a 2-D histogram of integer- or float-valued input data

        sfhist2 < in.rsf inp2=inp2.rsf > out.rsf n1= o1= d1= n2= o2= d2=
The output grid is not centered on the bins; it marks their "left edge".
I.e., the first sample holds the number of values between o1 and o1+d1

float d1=
histogram sampling for dimension 1
float d2=
histogram sampling for dimension 2
file inp2=
auxiliary input file name
int n1=
number of histogram samples in dimension 1
int n2=
number of histogram samples in dimension 2
float o1=
histogram origin for dimension 1
float o2=
histogram origin for dimension 2