From CloudModding OoT Wiki

C Multi-dimensional arrays are row-order. That is to say, each element within a row is assigned a contiguous location in ram

int v[3][2] = { 
    {0, 1},
    {2, 3}, 
    {4, 5}};

//ram
0x00 = 0
0x04 = 1
0x08 = 2
0x0C = 3
0x10 = 4
0x14 = 5

As such, v[3][0] == 4

Matrices

Matrices are defined as a float[4][4]

The following is a list of common matrices generated by the graphics utility functions in the SDK. Layouts are based on how they appear in memory.

Translation

1 0 0 0
0 1 0 0
0 0 1 0
x y z 1

Scalar

sx 0 0 0
0 sy 0 0
0 0 sz 0
0 0 0 1