A linear equation system
, with
being an
matrix and
, is called an overdetermined linear system. In general, it has no classical solution and you seek a vector
with the property:

Here,
denotes the Euclidean vector norm
.
This problem is called a least square problem. A stable method to solve it is based on factorizing
, with
being an
orthogonal matrix,
an
orthogonal matrix, and
an
matrix with the property
for all
. This factorization is called a singular value decomposition (SVD).
We write

with a diagonal
matrix
. If we assume that
has full rank, then
is invertible and it can be shown that

holds.
If we split
with
being an
submatrix, then the preceding equation can be simplified to:
SciPy provides a function called svd, which we use to solve this task:
import scipy.linalg...