Thanks Peeter for your reply.
So in my example, the non-orthonormal basis would be W and V would be its reciprocal frame?
By multiplying V*AW, I get the coordinates in the non-orthonormal basis W (in cols(W) directions) by dotting V*A ?
I cannot visualise an oblique projection. I understood the orthogonal one:
The orthogonal projection is P=U\cdotU*, where U is an orthonormal matrix (basis of a subspace) : U*\cdotU=I .
Now the projection of matrix A on U vectors is: PA=U*\cdotA\cdotU .
For the orthogonal projection, for a...
Well, first you have get a proper transfer function. You do that by dividing the numerator to the denominator to find the direct part of the sistem (D) : y(s) = D*u(s). So in your case that would be 1/2.
Now you have a proper transfer function (a first degree polynomial on a second degree...