1  use <matrix/m_replace.scad>
 2  
 3  module test_m_replace() {
 4      echo("==== test_m_replace ====");
 5  
 6      original_m = [
 7          [1, 2, 3, 4],
 8          [5, 6, 7, 8],
 9          [9, 10, 11, 12]
10      ];
11  
12      expected = [
13          [1, 2, 3, 4],
14          [5, 6, 70, 8],
15          [9, 10, 11, 12]
16      ];
17  
18      actual = m_replace(original_m, 1, 2, 70);
19  
20      assert(actual == expected);
21  
22  }
23  
24  test_m_replace();