10x0 matrix.
23x3 matrix.
3Remove row 0, column 1, and values above 6:
4col 0: locations 0 to 0
53 : 1
6col 1: locations 1 to 0
7col 2: locations 1 to 1
81 : 4
9col 3: locations 2 to 1
10Remove everything:
11col 0: locations 0 to -1
12col 1: locations 0 to -1
13col 2: locations 0 to -1
14col 3: locations 0 to -1
15uncompressed matrix.
16