On Fri, 2015-09-11 at 22:34 +0200, aitor_czr wrote:
> You are right Edward, i was thinking in the transposition matrix.
>
> > El 11/09/15 a las 19:32, Edward Bartolo escribió:
> >
> >
> > > only square matrices can
> > > have an inverse

If a square matrix is singular, i.e. the determinant is zero, no inverse
exists (a pseudoinverse and SVD exists though, see below).

For non-square, and square, matrices you can always define a
pseudo-inverse, (Moore-Penrose pseudoinverse), as well as calculate the
Singular Value Decomposition (SVD). The SVD is an efficient way to
calculate the pseudoinverse and least-squares fitting of data.