[Gnuplot-bugs] problems in tanh

[Yakov M. <ja...@ae...>]

Hi,

There's a hole in tanh function, the ranges are:
355-745.1
and a hole between -745.1 - -355 plus wrong values below -745.1 (1 
instead of -1) :

The version is 4.0 on aix:
  G N U P L O T
  Version 4.0 patchlevel 0
  last modified Thu Apr 15 14:44:22 CEST 2004
  System: 5.2

however the current debian/testing (x86) is affected as well.
Looks like the function checks for absolute value of the argument
to be above 745.1 and returns 1, tregradless if the argument is negative 
or positive. for some reason the calulations braks at absolute value of 
355.

Note: the thing became broken in one of the previos version, a very old 
version, in particular:

  G N U P L O T
  Amiga version 3.5
  patchlevel 3.50.1.17, 27 Aug 93
  last modified Fri Aug 27 05:21:33 GMT 1993

doens't suffer from the symptoms described above.

Regards,
Jack