Affine transform from x to the barycentric coordinates c.

Type:ndarray of double, shape (nsimplex, ndim+1, ndim)

This is defined by:

T c = x - r

At vertex j, c_j = 1 and the other coordinates zero.

For simplex i, transform[i,:ndim,:ndim] contains inverse of the matrix T, and transform[i,ndim,:] contains the vector r.