The package does not yet support matrices with complex elements. There are at least two approaches to including these. One is to have matrices with complex elements.
This probably means making new versions of the basic row and column operations for Real*Complex, Complex*Complex, Complex*Real and similarly for + and -. This would be OK, except that if I also want to do this for sparse matrices, then when you put these together, the whole thing will get out of hand.
The alternative is to represent a Complex matrix by a pair of Real matrices. One probably needs another level of decoding expressions but I think it might still be simpler than the first approach. But there is going to be a problem with accessing elements and it does not seem possible to solve this in an entirely satisfactory way.
Complex matrices are used extensively by electrical engineers and physicists and really should be fully supported in a comprehensive package.
You can simulate most complex operations by representing Z = X + iY by
/ X Y \ \ -Y X /Most matrix operations will simulate the corresponding complex operation, when applied to this matrix. But, of course, this matrix is twice as big as you would need with a genuine complex matrix library.