Issue #10445 has been updated by gogo tanaka. @Marc-Andre Lafortune Thank you for reply. OK, the answer is when we expect `Matrix` to behave something like `Array`, I mean.. ```ruby [1,2,3,4][1..2] #=> [2,3] Matrix[[1,2,3],[4,5,6],[7,8,9]][0..1, 0..1] #=> Matrix[[1,2], [4,5]] ``` Actually I am also one of people who expect such a behavior. Thanks. ---------------------------------------- Feature #10445: [PATCH 3/3] Extend Matrix#[] https://bugs.ruby-lang.org/issues/10445#change-50027 * Author: gogo tanaka * Status: Feedback * Priority: Normal * Assignee: Marc-Andre Lafortune * Category: lib * Target version: ---------------------------------------- I've made patches which Matrix#[] returns new vector if either arguments is range, and returns new matrix, if both arguments are range. Like below. ```ruby # matrix[row, column] -> obj or nil # matrix[row, col_range] -> new_vector or nil # matrix[row_range, column] -> new_vector or nil # matrix[row_range, col_range] -> new_matrix or nil Matrix.diagonal(9, 5, -3)[1, 1] => 5 Matrix.diagonal(9, 5, -3)[1, 0..1] => Vector[0, 5] Matrix.diagonal(9, 5, -3)[0..1, 0] => Vector[9, 0] Matrix.diagonal(9, 5, -3)[0..1, 0..1] => Matrix[[9, 0], [0, 5]] ``` I'm not sure `matrix[row, col_range] ` should return `vector` or `matrix` But from my view, it's fine. I'm not in a hurry. Take your time. ---Files-------------------------------- add_test.patch (1.05 KB) implement_matrix.rb.patch (1.96 KB) update_NEWS.patch (825 Bytes) -- https://bugs.ruby-lang.org/