Create a Matrix with Specific Pattern for Changing Values

How can I create a matrix such as this one where the change in value is some dx and each column varies differently?

[-3*pi/4 -3*pi/4 -3*pi/4;
   -3*pi/4 -3*pi/4 -3*pi/8;
   -3*pi/4 -3*pi/4 0;
   -3*pi/4 -3*pi/8 -3*pi/4;
   -3*pi/4 -3*pi/8 -3*pi/8;
   -3*pi/4 -3*pi/8 0;
   -3*pi/4 0 -3*pi/4;
   -3*pi/4 0 -3*pi/8;
   -3*pi/4 0 0;
   -3*pi/8 -3*pi/4 -3*pi/4;
   -3*pi/8 -3*pi/4 -3*pi/8;
   -3*pi/8 -3*pi/4 0;
   -3*pi/8 -3*pi/8 -3*pi/4;
   -3*pi/8 -3*pi/8 -3*pi/8;
   -3*pi/8 -3*pi/8 0;
   -3*pi/8 0 -3*pi/4;
   -3*pi/8 0 -3*pi/8;
   -3*pi/8 0 0;
   0 -3*pi/4 -3*pi/4;
   0 -3*pi/4 -3*pi/8;
   0 -3*pi/4 0;
   0 -3*pi/8 -3*pi/4;
   0 -3*pi/8 -3*pi/8;
   0 -3*pi/8 0;
   0 0 -3*pi/4;
   0 0 -3*pi/8;
   0 0 0]

Answer 1

[Kelly Kearney]

Create a grid of values, then unwrap:

xval = [-3*pi/4 -3*pi/8 0];
[a,b,c] = ndgrid(x,x,x);
x = [c(:) b(:) a(:)]