Language Reference
EXPANDGRID Function
EXPANDGRID (x1, x2 <, x3> …<, x15>) ;
This function is supported by the IML procedure and the iml action.
The EXPANDGRID function is part of the IMLMLIB library. The arguments to the EXPANDGRID function are k vectors, 
. The EXPANDGRID function returns a matrix that contains the Cartesian product of elements from the specified vectors. If the ith argument has 
elements, the return matrix has 
rows and k columns.
Each row of the result contains a combination of elements of the input vectors. The first row contains the elements (x1[1], x2[1],…, xk[1]). The second row contains the elements (x1[1], x2[1],…, xk[2]). The first column varies the slowest, and the last column varies the fastest.
The following statement create a matrix of 0s and 1s. Each row is a vertex of the three-dimensional unit cube.
g = ExpandGrid(0:1, 0:1, 0:1);
print g;
Figure 147: A Cartesian Product of Three Vectors
| g | ||
|---|---|---|
| 0 | 0 | 0 |
| 0 | 0 | 1 |
| 0 | 1 | 0 |
| 0 | 1 | 1 |
| 1 | 0 | 0 |
| 1 | 0 | 1 |
| 1 | 1 | 0 |
| 1 | 1 | 1 |
You can use the EXPANDGRID function to generate a complete factorial design from the set of factors. You can also use it to evaluate a multivariate function on a dense grid of points. For example, the following statements evaluate the bivariate cubic polynomial 
on a grid of points in the region 
:
vx = do(-2, 2, 0.1);
vy = do(-2, 2, 0.1);
g = ExpandGrid(vx, vy); /* grid on [-2,2] x [-2,2] */
x = g[,1]; y = g[,2];
z = x##3 - y##2 - 2#x + 1;