Removing Dimensions from Matrices in Octave or MATLAB - squeeze()

For many math applications you want to run through many variables all at once and gather data. Of course, having several variables that will lead to n-dimensional matrices.

For example I was converting from a spherical coordinate system to a Cartesian and experimenting with what the x,y,z coordinates would be for two changing angles.  This lead to a rank (3 by n by m)  3-dimensional matrix where first dimension is the xyz, the second is angle one and the last is angle two.  To get the matrix for any single variable, do the following: extract a submatrix and then use squeeze to get a single 3 by n or 3 by m matrix.

Example:

Let A = [3*n*m]  say=

size(A) = 3 32 32

a = A(:,1,m)   # takes single dimension matrix from 3*m*n using column one of second dimension

size(a) = 3 1 32

a = squeeze(a) 

size(a) = 3 32

squeeze() looks for the singleton dimension and then does the tedious  matrix copy and paste operations for you.


Of course this gives you one of many, then duplicate for the remainder.