[Maxima-bugs] [ maxima-Bugs-1190421 ] lisp error in plot3d()

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Bugs item #1190421, was opened at 2005-04-26 10:51
Message generated for change (Settings changed) made by robert_dodier
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>Category: Lisp Core - Plotting
Group: None
Status: Open
Resolution: None
Priority: 5
Submitted By: Nobody/Anonymous (nobody)
Assigned to: Nobody/Anonymous (nobody)
Summary: lisp error in plot3d()

Initial Comment:
Here is the error:

(%i1) plot3d(x**y,[x,0,1],[y,0,1]);
Maxima encountered a Lisp error:

 Error in CATCH [or a callee]: Expected a LONG-FLOAT 

Automatically continuing.
To reenable the Lisp debugger set *debugger-hook* to nil.
(%i2) 

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Comment By: Raymond Toy (rtoy)
Date: 2005-08-19 12:18

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The actual problem is that when we compute 0.0^0.0, the
function returns T.  (I think this was done to support
adaptive plotting where non-number means a singularity of
some sort.  But we don't do adaptive 3-D plotting.)

I'd really like it if we could use Lisp conditions to signal
these kinds of errors so we can handle them better.

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Comment By: Barton Willis (willisbl)
Date: 2005-04-26 20:36

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Avoiding x=0 and y=0 is a workaround

   plot3d(x^y,[x,0.01,1],[y,0.01,1]);

But the error message ' Error in CATCH [or a callee]:
Expected a LONG-FLOAT' is goofy.  There is  something wrong that
needs to be fixed.

Barton


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