Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
1995
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*November
*December
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 1995

[Date Index] [Thread Index] [Author Index]

Search the Archive

Singular Matrix error in FindRoot ?

  • To: mathgroup at smc.vnet.net
  • Subject: [mg2750] Singular Matrix error in FindRoot ?
  • From: a_kowald at chemie.fu-berlin.de (Axel Kowald)
  • Date: Wed, 13 Dec 1995 02:00:55 -0500
  • Organization: Kristallographic Institute FU Berlin

Hi

I'm using FindRoot on a fairly complicated function with several parameters and
one variable. For certain parameter values I get the error message:

            LinearSolve::sing: Matrix {{0.}} is singular

FindRoot continues, but never finishes. I think the problem is that some terms of
the function become very! small respectively large, so that there might be an
internal underflow.  However, the really annoying thing is that FindRoot seems to
"hang" after that and never finishes. This is especially bad for me, because I
calculate solutions for many different parameter values in a Table[]. But if
FindRoot hangs I have to interrupt it by hand and never finish the table.


Any ideas are wellcomed.


		Axel Kowald



  • Prev by Date: Re: Mathematica 2.2.3 on Windows 95
  • Next by Date: Re: Help : Plotting vectors in 3D Graphics
  • Previous by thread: Singular Matrix error in FindRoot ?
  • Next by thread: Speedcomparison of Mathematica on Various Machines