matrix:submatrix

matrix:submatrix matrix r1 c1 r2 c2

Reports a new matrix object, consisting of a rectangular subsection of the given matrix. The rectangular region is from row r1 up to (but not including) row r2, and from column c1 up to (but not including) column c2.

Here is an example:

let m matrix:from-row-list [[1 2 3][4 5 6][7 8 9]]
print matrix:submatrix m 0 1 2 3 ; matrix, row-start, col-start, row-end, col-end
                                 ; rows from 0 (inclusive) to 2 (exclusive),
                                 ; columns from 1 (inclusive) to 3 (exclusive)
=> {{matrix:  [ [ 2 3 ][ 5 6 ] ]}}