HISTO2 calculates histogram of each column
R=HISTO2(Y)
R=HISTO(...)
R is a struct with th fields
R.X are the bin-values
R.H is the frequency of occurence of value X
R.N are the number of valid (not NaN) samples
more histogram-based results can be obtained by HIST2RES2
see also: HISTO, HISTO2, HISTO3, HISTO4
REFERENCE(S):
C.E. Shannon and W. Weaver 'The mathematical theory of communication' University of Illinois Press, Urbana 1949 (reprint 1963).