[Reduce-algebra-developers] Reduce: problem with package linalg

[Prof T. R. <Pro...@pr...>]

Hi,

have run into a problem with package lin_alg (and package sparse 
also has similar issues).  Can anyone fix?

Using redcsl (rev 6339) I execute the following script

on rounded; print_precision 4$
load linalg;
a:=mat((-2,3),(5,7));
svda:=svd(a);
b:=a/3;   svdb:=svd(b);
c:=a/2;   svdc:=svd(c);
end;

To get the two different failures for matrices b and c.

1: in "tmp.txt"$
      [-2  3]
a := [     ]
      [5   7]
svda := {
          [0.1722   - 0.9851]
          [                 ]
          [0.9851   0.1722  ]
          ,
          [8.713    0  ]
          [            ]
          [  0    3.328]
          ,
          [0.5257   0.8507  ]
          [                 ]
          [0.8507   - 0.5257]
          }
      [ - 0.6667    1  ]
b := [                ]
      [  1.667    2.333]
***** svd: Non-numeric matrix element at position ( 1 , 1 )
Cont? (Y or N)
?y
      [ - 1  1.5]
c := [         ]
      [2.5   3.5]

And then redcsl just hangs, and I have to kill the process.  Could 
someone advise on a work around (for larger matrices).

The package sparse also causes similar failure.

Tony

-- 
---------------------------------------------------------------------
Four books and a toolbox:

* (2020) Linear Algebra for the 21st Century
Oxford University Press. isbn: 978-0-19-885640-5, 978-0-19-885639-9
https://global.oup.com/academic/product/linear-algebra-for-the-21st-century-9780198856399

* (2015) Model emergent dynamics in complex systems
SIAM, Philadelphia. isbn: 9781611973556.
https://epubs.siam.org/doi/10.1137/1.9781611973563

* (2009) Elementary calculus of financial mathematics
SIAM, Philadelphia. isbn: 978-0-898716-67-2.
https://epubs.siam.org/doi/10.1137/1.9780898718225

* (1994) A one-dimensional introduction to continuum mechanics
World Sci. isbn: 978-981-02-1913-0.

* (2020) with John Maclean, and J. E. Bunder; Equation-Free
function toolbox for Matlab/Octave.
http://github.com/uoa1184615/EquationFreeGit

Emeritus Professor A.J. Roberts,  FAustMS
School of Mathematical Sciences,  University of Adelaide
https://profajroberts.github.io/
mailto:Pro...@pr...
http://orcid.org/0000-0001-8930-1552