Loop-free histogramming of each column of an input matrix

Before there was histcounts(), we would use histc(), which is no longer recommended by TMW. But histc() could calculate the column-wise histogram of an input matrix,

A =[ 9     5     2     1     5     3     3     2     2     5
     1     8     3     1     7     4     3     2     2     6
     1     3     1     1     8     6     4     4     2     4
     1     3     1     6     4     2     1     2     9     7
     2     1     6     3     2     2     1     1     9     1
     2     3     1     1     7     5     4     2     1     5
     1     1     4     2     1     8     6     5     4     5];

H=histc(A,1:10)

H = 10×10

4 2 3 4 1 0 2 1 1 1 2 0 1 1 1 2 0 4 3 0 0 3 1 1 0 1 2 0 0 0 0 0 1 0 1 1 2 1 1 1 0 1 0 0 1 1 0 1 0 3 0 0 1 1 0 1 1 0 0 1 0 0 0 0 2 0 0 0 0 1 0 1 0 0 1 1 0 0 0 0 1 0 0 0 0 0 0 0 2 0 0 0 0 0 0 0 0 0 0 0

whereas histcounts does not seem to have this capability. Is there a replacement for this capability somewhere in modern Matlab, aside from an Mcoded for-loop?

Answer 1

[Dave B]

This is somewhere between workaround and hack, but you could do it with histcounts2:

X=rand(5);
a=histcounts2(X,ones(5).*(1:5),linspace(0,1,10),.5:5.5);
b=histc(X,linspace(0,1,10));
isequal(a,b(1:end-1,:))

ans = logical
   1

[Matt J]

Yep. That works. Too bad about the extra memory allocation required with ones(N).*(1:N)