How to remove ith column of a matrix using for loop-CodePudding

Using MatLab, I am attempting to begin with a matrix,

column1	column2	column3	column4	column5
1	4	7	10	11
2	5	8	11	12
3	6	9	12	13

and use a for loop to obtain 5 matrices, one with each of the columns removed, according to:

column2	column3	column4	column5
4	7	10	11
5	8	11	12
6	9	12	13

column1	column3	column4	column5
1	7	10	11
2	8	11	12
3	9	12	13

column1	column2	column4	column5
1	4	10	11
2	5	11	12
3	6	12	13

column1	column2	column3	column5
1	4	7	11
2	5	8	12
3	6	9	13

column1	column2	column3	column4
1	4	7	10
2	5	8	11
3	6	9	12

Please note that it is extremely important that this be done IN A LOOP, so as to be replicable for an arbitrary number of columns, as I have managed to code this for a known number of columns already.

Thank you in advance for any help.

CodePudding user response：

That's a pretty straightforward problem for Matlab or Octave. I wonder what your problem was?

m = [
  1 4 7 10 11
  2 5 8 11 12
  3 6 9 12 13
];

outmatrices = {};

for col = 1:size(m,2)
  outmatrices{end 1} = [m(:,1:col-1), m(:,col 1:end)];
end

outmatrices

CodePudding user response：

You could use arrayfun( ) for this, which will handle any matrix size and hide the looping behind the function call. E.g.,

result = arrayfun(@(k)[m(:,1:k-1),m(:,k 1:end)],1:size(m,2),'uni',false);

The result will be a cell array with the various matrices as the cell elements.