[Ecls-list] How to get floating point underflow to yield zero?

Juan Jose Garcia-Ripoll jjgarcia at users.sourceforge.net
Tue May 6 13:09:59 UTC 2008

On Wed, Apr 30, 2008 at 5:34 PM, Robert Dodier <robert.dodier at gmail.com> wrote:
>  In working through the Maxima test suite, there is at least one error
>  which is caused by floating point underflow. Other Lisp implementations
>  let floating point underflow yield zero, and that is what Maxima expects.
>  It appears that floating point underflow causes an error in ECL.
>  How can I convince ECL to yield zero instead? Thanks for your help.

You can disable certain floating point conditions using (SI:TRAP-FPE
condition-name boolean). So in your case it would be (SI:TRAP-FPE
'FLOATING-POINT-UNDERFLOW NIL) I do not know whether this makes the
outcome of your underflowed operation zero or not.


Facultad de Fisicas, Universidad Complutense,
Ciudad Universitaria s/n Madrid 28040 (Spain)

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