[Octave-bug-tracker] [bug #38961] print freezes when printing certain fplots

[Mike Miller]

Update of bug #38961 (project octave):

              Item Group:                   Crash => Performance            
        Operating System:                  Mac OS => Any                    

    _______________________________________________________

Follow-up Comment #3:

Ok, I looked at this a little deeper. The default tolerance is the same in all
cases, 2e-3. Fplot iteratively interpolates the given function over increasing
ranges of x until the maximum error falls below that threshold. Your
particular function simply never converges, at least using the calculation of
error in there now.

I think convergence is failing on certain functions that have very small
values near the origin where interpolation is slightly off, such that small
absolute errors become large relative errors. Besides your function "x^2 *
sin(x)", another example function that doesn't converge is "x^2 + x^4".
Another is "(exp(x)-1)^2".

It could be argued that the method for calculating convergence could be
improved to fix this problem. Needs input from someone with a stronger
mathematical background than mine.

    _______________________________________________________

Reply to this item at:

  <http://savannah.gnu.org/bugs/?38961>

_______________________________________________
  Message sent via/by Savannah
  http://savannah.gnu.org/