#1478 Plot leaves range with jacobi functions

closed
nobody
5
2009-01-01
2008-08-16
No

Hello,

I am working with jacobi elliptic functions with both 2d and parametric graphs and am finding they leave the domain when I use these functions under multiplication. I believe the numeric package is running out of memory or the plotter makes some similar error. How do I fix this, or how can it be fixed?

specifically try jacobi_dn()*jacobi_dn() with two frequencies (one about one tenth the other) for times exceeding 48.

This reliably causes the graph to spiral out of control and I was wondering if there was a fix.

Discussion

    • summary: Plot leaves domain with jacobi functions --> Plot leaves range with jacobi functions
     
  • Robert Dodier
    Robert Dodier
    2008-08-24

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    Thanks for this report. Please post an example in the form of specific Maxima expressions which we can use to reproduce the error. Thanks for your help. Robert Dodier

     
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    jacobi_cn(t,.7)*jacobi_cn(.1*t,.9)

    wxplot2d([%], [t,0,40])

     
  • Raymond Toy
    Raymond Toy
    2008-08-30

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    This is a bug in the computation of jacobi_cn. Try, eg, jacobi_cn(100,.7)

    The algorithms for computing jacobi_cn and jacobi_dn need to be examined. jacobi_sn appears to be ok.

    Changing category to floating point instead of plotting.

     
  • Raymond Toy
    Raymond Toy
    2008-08-30

    • labels: 840510 --> Lisp Core - Floating point
     
  • Raymond Toy
    Raymond Toy
    2009-01-01

    This should be fixed in CVS, ellipt.lisp, rev 1.30.

     
  • Raymond Toy
    Raymond Toy
    2009-01-01

    • status: open --> closed