Can you help me to correct this error?

Hello guys, I have code here:

clc
clear all
A=[0,0,0;0,0,0;0,0,0;0,0,0;1,5,4;7,6,9;3,2,8];
[m,n]=size(A);
count=0;
            while isempty(A)==0
            [target, min_idx]=min(A(A~=0));
            [rmin,cmin]=ind2sub(size(A),find(A==target)); 
             for c=1:rmin                 
                if A(c,cmin)==target                 
                     count=count+1;
                     A(c,cmin)=0; 
                end
             end
            end
 disp(count); 

And when I run the code, i got this result:

 Error using  == 
Matrix dim

It has problem in this line

 [rmin,cmin]=ind2sub(size(A),find(A==target)); 

I want to find the minimum number in matrix A and replace it by 0, then count the number of move. The loop will run until matrix A becomes zero.

Please help me to correct it, thank you very much!

[madhan ravi]

Show explicitly how your output A should look like for the given example above.

[Lomi Vo]

I expect the count=9 for the final result but I want to know why I wrong

[Stephen23]

nnz(A~=0)

[Lomi Vo]

Thank you so much!

Answer 1

[Jan]

while isempty(A)==0 will not work, because the matrix A does not change its size. I guess you mean:

while any(A(:) ~= 0)
% Or short: while any(A, 'all')
% Or        nnz(A~=0)  % as Stephen has suggested

The error occurred, when A does not contain elements, which differ from 0. Then:

[target, min_idx]=min(A(A~=0));

replies an empty target and A==target is not defined.

Use logical indexing inside the loop:

target   = min(A(A~=0));
index    = (A == target);
A(index) = 0;
count    = count + nnz(index);

An easier approach without a loop:

count = numel(unique(A(A~=0)))