Apply an affine transformation.
The given matrix and offset are used to find for each point in the output the corresponding coordinates in the input by an affine transformation. The value of the input at those coordinates is determined by spline interpolation of the requested order. Points outside the boundaries of the input are filled according to the given mode. The output shape can optionally be given. If not given it is equal to the input shape. The parameter prefilter determines if the input is pre-filtered before interpolation, if False it is assumed that the input is already filtered.
The matrix must be two-dimensional or can also be given as a one-dimensional sequence or array. In the latter case, it is assumed that the matrix is diagonal. A more efficient algorithms is then applied that exploits the separability of the problem.