svd_circle, a Python code which analyzes a linear map of the unit circle caused by an arbitrary 2x2 matrix A, using the singular value decomposition (SVD).

The singular value decomposition has uses in solving overdetermined or underdetermined linear systems, linear least squares problems, data compression, the pseudoinverse matrix, reduced order modeling, and the accurate computation of matrix rank and null space.

The singular value decomposition of an M by N rectangular matrix A has the form

        A(mxn) = U(mxm) * S(mxn) * V'(nxn)
where Note that the transpose of V is used in the decomposition, and that the diagonal matrix S is typically stored as a vector.


The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.


svd_circle is available in a MATLAB version and a Python version.

Related Data and Programs:

svd_lls, a Python code which uses the singular value decomposition (SVD) to construct and plot the best affine and linear relationships in the sense of least square, between two vectors of data.

svd_snowfall, a Python code which reads a file containing historical snowfall data and analyzes the data with the Singular Value Decomposition (SVD).

svd_test, a Python code which demonstrates the singular value decomposition (SVD) for a simple example.


  1. Lloyd Trefethen, David Bau,
    Numerical Linear Algebra,
    SIAM, 1997,
    ISBN: 0-89871-361-7,
    LC: QA184.T74.

Source Code:

Last revised on 31 March 2022.