select m*m matrix from m*n matrix

Could you please add more details on how the number of combinations can be c(n,m).

As per me if you do simple selection (without crossing boundaries of matrix) then the number of combinations will be (n-m) and if you do complex selection (by crossing the boundaries of matrix) then the number of combination will be nxm.

Crossing the boundaries of matrix mean considering the first element is adjacent to last element in a row and first element is adjacent to last element in a column.

-Pradeep

pradeep_agrawal

Could you please add more details on how the number of combinations can be c(n,m).

As per me if you do simple selection (without crossing boundaries of matrix) then the number of combinations will be (n-m) and if you do complex selection (by crossing the boundaries of matrix) then the number of combination will be nxm.

Crossing the boundaries of matrix mean considering the first element is adjacent to last element in a row and first element is adjacent to last element in a column.

-Pradeep

suppose we take a 2*5 matrix ie
1 5 7 8 9
2 6 4 8 9
then from this i have to select all 2*2 matrices
so the possibilities are
1 5 1 7 1 8 1 9 5 7 5 8 5 9 7 8 7 9 8 9
2 6, 2 4, 2 8, 2 9, 6 4, 6 8, 6 9, 4 8, 4 9, 8 9
so its c(5,2)=10 which is equal to the no of selection.

pradeep_agrawal

Could you please add more details on how the number of combinations can be c(n,m).

As per me if you do simple selection (without crossing boundaries of matrix) then the number of combinations will be (n-m) and if you do complex selection (by crossing the boundaries of matrix) then the number of combination will be nxm.

Crossing the boundaries of matrix mean considering the first element is adjacent to last element in a row and first element is adjacent to last element in a column.

-Pradeep

I didnt get this Pradeep, How is it n-m and n*m can you give a small example ?