From: SourceForge.net <noreply@so...>  20030225 16:23:11

Bugs item #691941, was opened at 20030223 20:11 You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=691941&group_id=4933 Category: Lisp Core Group: None Status: Open Resolution: None Priority: 5 Submitted By: M. L. Murphy (mlmurphy) >Assigned to: Raymond Toy (rtoy) Summary: plot3d fails with bessel funcs Initial Comment: Hello, Maxima team. I'm a new user and am amazed with what I'm able to accomplish in Maxima. I'm having a little trouble. I'm trying to make a bessel function plot, and it keeps failing. For instance: (C1) plot3d(bessel_j[0](x),[x,0,10],[y,0,2*%pi],['transform_xy,polar_to_xy]); Error: ((MQAPPLY SIMP) (($BESSEL_J SIMP ARRAY) 0) 0.33333333333333331) is not of type (OR RATIONAL LISP:FLOAT). Fast links are on: do (si::usefastlinks nil) for debugging Error signalled by LISP:FLOAT. Broken at LISP:FLOAT. Type :H for Help. Nothing I do seems to allow the plot to complete, including using BESSELEXPAND and making the order 1/2: (C1) besselexpand:true; (D1) TRUE (C2) plot3d(bessel_j[1/2](x),[x,0.0001,10],[y,0,2*%pi],['transform_xy,polar_to_xy]); Error: ((MTIMES SIMP) 0.0099999999833333339 ((MEXPT SIMP) 2 (# 1 2)) ...) is not of type (OR RATIONAL LISP:FLOAT). Fast links are on: do (si::usefastlinks nil) for debugging Error signalled by LISP:FLOAT. Broken at LISP:FLOAT. Type :H for Help. My maxima information:  Maxima version: 5.9.0 Maxima build date: 22:24 2/9/2003 host type: i386redhatlinuxgnu lispimplementationtype: Kyoto Common Lisp lispimplementationversion: GCL25.0  (I'm using the Redhat RPMs on Redhat 8.0.) A bug fix would be great, but if it's not possible, I really would like to get a workaround, as I'd like to get a picture of the plot for a paper. If there is a simple workaround, could you please let me know?  >Comment By: Raymond Toy (rtoy) Date: 20030225 11:32 Message: Logged In: YES user_id=28849 Yes, this is a bug in bessel_j wherein it doesn't give a numerical answer even when the arg is a float. As a workaround, use j0(x) insetad of bessel_j[0](x). Or you can set numer:true before plotting, or use plot3d(bessel_j[0](x),[x,0,10],[y,0,2*%pi],['transform_xy,polar_to_xy]), numer;  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=691941&group_id=4933 