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...