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CYCOL: Matrices with random cyclic columns

from the MMDELI

Matrix Generator CYCOL
Source: Nicholas Higham, Robert Schrieber and David Hough
Discipline: numerical linear algebra
Language: Java applet
Output format: Matrix Market format

This is a Java applet which generates matrices consisting of P random columns with elements drawn uniformly from (-1,1) . These are repeated (in order) until all the columns are filled out. The matrix is rank deficient unless the period exceeds the number of columns.

Such matrices can lead to underflow problems for Gaussian elimination. See the report in NA Digest Volume 89 Issue 3 (Jan 22, 1989) which shows how such matrices were (accidentially) generated by the LINPACK test suite.

This generator was developed by Bruce Miller of NIST based on Nick Higham's Test Matrix Toolbox for MATLAB.


Nnumber of rows.
Mnumber of columns.
Pperiod (number of random columns repeated).


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Last change in this page: Wed Sep 22 13:34:19 US/Eastern 2004 [Comments: ]