[Octave-bug-tracker] [bug #38961] fplot needs adaptive scaling algorithm

[Rik]

Update of bug #38961 (project octave):

              Item Group:             Performance => Inaccurate Result      
                  Status:               Need Info => Confirmed              
                 Summary: print freezes when printing certain fplots => fplot
needs adaptive scaling algorithm

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Follow-up Comment #5:

I overhauled fplot in this changeset
(http://hg.savannah.gnu.org/hgweb/octave/rev/b34202b24212).  I upgraded it to
be more Matlab compatible and I added an additional stopping condition to
detect when the algorithm is failing.  This works for functions which end up
having a relative tolerance that won't converge because the function value at
0 is near 0.  However, the real long-term fix is to add an adapative scaling
algorithm of the sort used in the quadrature routines.  Basically, the current
algorithm is no good if the function contains discontinuities.  Try


fplot (@tan, [-2,2])


to see just how bad.


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