One way to generate an idempotent matrix is to use the formula:
where I is the identity matrix, n is the number of rows, and i is a column vector of 1s of dimension n.
This matrix is by definition orthogonal so that the rows are independent.
I have included an example below of how this can be done in IML.
m2=m*m;*check for idempotency;
print m m2;
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