public inbox for gsl-cvs@sourceware.org
help / color / mirror / Atom feed
* gsl/linalg linalg_simple.c
@ 1999-10-17 23:47 jt
  0 siblings, 0 replies; 2+ messages in thread
From: jt @ 1999-10-17 23:47 UTC (permalink / raw)
  To: gsl-cvs

CVSROOT:	/cvs/gsl
Module name:	gsl
Changes by:	jt@sourceware.cygnus.com	99/10/17 23:47:51

Modified files:
	linalg         : linalg_simple.c 

Log message:
	i was trying to use the SVD routine in linalg/linalg_simple.c,
	and it was producing singular values that were saturating at
	about 10^-6, even though the true values were much smaller than
	that.  i was able to "fix" the problem by replacing
	GSL_DBL_EPSILON with GSL_DBL_MIN, but i am suspicious of this
	solution.  perhaps the true test should be GSL_DBL_EPSILON times
	some scale factor? despite the fact that SVD always seems a
	little magical to me, and despite the likelihood that it will
	break some other case, i've gone ahead and cvs commit'd the
	change.  my own testing code, i must confess, is too convoluted
	to include here, but the test i did was a 10x10 Hilbert matrix:
	A[i][j] = 1/(i+j+2), i=0..9, j=0..9


^ permalink raw reply	[flat|nested] 2+ messages in thread

* gsl/linalg linalg_simple.c
@ 1999-02-09 21:55 jungman
  0 siblings, 0 replies; 2+ messages in thread
From: jungman @ 1999-02-09 21:55 UTC (permalink / raw)
  To: gsl-cvs

CVSROOT:	/cvs/gsl
Module name:	gsl
Changes by:	jungman@egcs.cygnus.com	99/02/09 21:55:10

Modified files:
	linalg         : linalg_simple.c 

Log message:
	minor twiddling


^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~1999-10-17 23:47 UTC | newest]

Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
1999-10-17 23:47 gsl/linalg linalg_simple.c jt
  -- strict thread matches above, loose matches on Subject: below --
1999-02-09 21:55 jungman

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).