Find first non-zero column of a matrix

How do I, given a matriz A, tell MATLAB to find the index of the leftmost non-zero column of said matrix?

Answer 1

[dpb]

>> A=[zeros(5) randn(5)]; A=A(:,randperm(10));  % sample dataset
A =
 -0.7440    1.0223    0   -0.7062   0    0.1257         0    1.2390         0         0
 -0.3744   -1.4192    0   -1.0207   0    0.6963         0    0.8987         0         0
  0.4241    2.5467    0    1.1340   0    1.7395         0   -1.1501         0         0
  0.1141   -0.3580    0    0.0385   0    0.6654         0   -0.2642         0         0
 -0.5111    0.4013    0    0.2309   0    0.6875         0   -1.6252         0         0
>> find(any(A),1)  % first column nonzero
ans =
   1
>>

That one seems too easy; let's try again...

>> A=A(:,randperm(10)); 
A =
       0   -0.7440    0   0    1.0223    1.2390         0         0    0.1257   -0.7062
       0   -0.3744    0   0   -1.4192    0.8987         0         0    0.6963   -1.0207
       0    0.4241    0   0    2.5467   -1.1501         0         0    1.7395    1.1340
       0    0.1141    0   0   -0.3580   -0.2642         0         0    0.6654    0.0385
       0   -0.5111    0   0    0.4013   -1.6252         0         0    0.6875    0.2309
>> find(any(A),1)
ans =
   2
>>

OK, that's more difficult and illustrates it does work as expected...

Answer 2

[Azzi Abdelmalek]

A=randi([0 2],20,8)
[~,out]=max(sum(logical(A)))