# [Maxima] (Newbie) Problem plotting numerical integrations

Judy Toth judyt2009 at comcast.net
Tue Sep 2 19:48:29 CDT 2008

```I am using a different version, maybe that's it.  Download version 5.16.3, the latest, at sourceforge.net

Rich

------------Original Message------------
From: Tim Day <timday at bottlenose.demon.co.uk>
To: maxima at math.utexas.edu
Date: Tue, Sep-2-2008 8:33 PM
Subject: Re: [Maxima] (Newbie) Problem plotting numerical integrations

On Tue, 2008-09-02 at 19:19 -0400, Richard Hennessy wrote:
> Try
> plot3d('(r(x,y)),[x,-1,1],[y,-1,1],[grid,50,50],[gnuplot_pm3d,true]);
> that worked for me.

Strange; no luck here (although the error changes)...

-----
Maxima 5.13.0 http://maxima.sourceforge.net
Using Lisp GNU Common Lisp (GCL) GCL 2.6.8 (aka GCL)
Dedicated to the memory of William Schelter.
This is a development version of Maxima. The function bug_report()
provides bug reporting information.
(%i1) V(p):=max(0,1-sqrt(p.p));
(%o1)                   V(p) := max(0, 1 - sqrt(p . p))
(%o2)           r(x, y) := quad_qags(V([x, y, z]), z, - 1, 1)
1
(%i3)
plot3d('(r(x,y)),[x,-1,1],[y,-1,1],[grid,50,50],[gnuplot_pm3d,true]);

Maxima encountered a Lisp error:

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

Automatically continuing.
To reenable the Lisp debugger set *debugger-hook* to nil.
-----
(Same thing happens with romberg too).

What version of maxima/lisp are you using ?

Tim

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