sjkaliski/numbers.js — pull request #70 by revivek (2012-12-22 01:55:12+00:00)
Title: Added SquareMatrix, determinant (accurate past 4x4)

Hey all, made some changes:

1. I added SquareMatrix. To calculate the determinant, it checks if we can "downcast" to SquareMatrix, then calls determinant() on this.

2. Our existing implementation of determinant() was not correct. [It evaluated to around 13 for this matrix](http://www.wolframalpha.com/input/?i=determinant+of%5B%5B3%2C+-1%2C+0.2%2C+2%5D%2C+%5B3%2C+1%2C+5%2C+1%5D%2C+%5B6%2C+3%2C+-5%2C+0%5D%2C+%5B7%2C+7%2C+7%2C+1%5D%5D). This commit should fix it, however note it employs recursion.

3. I implemented removeRow(k) and removeColumn(k).

These changes comes with tests that pass.