svd_snowfall, a FORTRAN90 code which demonstrates the use of the Singular Value Decomposition (SVD) to analyze a set of historical snowfall data, with plots created by gnuplot().
The snowfall data consists of records for the winters of 1890-1891 to 2016-2017, of the snowfall in inches, over the months from October to May, as measured at Michigan Tech.
This data can be regarded as an 8 by 127 matrix A. Applying the singular value decomposition produces the factors
A = U * S * V'and it is the purpose of this library to consider what these factors indicate about the snowfall data.
The sample problem writes files that can be processed by GNUPLOT to create plots.
The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.
svd_snowfall is available in a C version and a C++ version and a FORTRAN90 version and a MATLAB version and a Python version.
FINGERPRINTS, a dataset directory which contains a few images of fingerprints.
gnuplot_test, FORTRAN90 codes which write data and command files so that gnuplot() can create plots.
SVD_BASIS, a FORTRAN90 code which computes a reduced basis for a collection of data vectors using the SVD.
SVD_TRUNCATED, a FORTRAN90 code which demonstrates the computation of the reduced or truncated Singular Value Decomposition (SVD) of an M by N rectangular matrix, in cases where M < N or N < M.
TIME_SERIES, a dataset directory which contains examples of files describing time series.