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From: rimey@ucbarpa.Berkeley.EDU (Ken Rimey)
Newsgroups: comp.sys.mac,sci.math,sci.math.symbolic
Subject: Re: MATHEMATICA on the MAC II -- Summary
Summary: Macsyma can too solve ode's.
Message-ID: <27535@ucbvax.BERKELEY.EDU>
Date: 14 Jan 89 03:05:15 GMT
References: <66958GFX@PSUVM> <67374GFX@PSUVM>
Sender: usenet@ucbvax.BERKELEY.EDU
Reply-To: rimey@ucbarpa.Berkeley.EDU (Ken Rimey)
Organization: University of California, Berkeley
Lines: 47

In article <67374GFX@PSUVM> GFX@PSUVM.BITNET writes:
>...  I also received some comments on a soon-to-be-released symbolic
>processor "Maple" developed by U. of Waterloo.

Maple has been available under Unix for years.

>....
>Just in case that might be of interest to anyone: my question was prompted
>by the remark made by a prof of optimal control that MacSyma was unable to
>solve even relatively simple differential equations.  The specifics:
>
>                  x'(t) = (N - x(t)) * (a + bx(t))

The remark is wrong.

	[arpa]-> vaxima

	     Vaxima 2.11 in Franz Lisp opus 43.1
	  Fri Aug 28 15:05:23 1987

	(c_1) load("ode2");

	/g/2.0/mac/share/ode2.l being loaded.
	;; Loading file "/g/2.0/mac/share/ode2.l"

	(d_1) 			   /g/2.0/mac/share/ode2.l

	(c_2) eq: 'diff(x,t) = (N - x) * (a + b * x);

				    dx
	(d_2) 			    -- = (n - x) (a + b x)
				    dt

	(c_3) ode2(eq, x, t);

			    - log(- n + x) + log(a + b x)
	(d_3) 		    ----------------------------- = %c + t
				       a + b n

>From what I read, I am inclined to think that symbolic processors have
>a rather limited expertise...  Stephane

Maybe, but not as limited as you suggested.

					Ken Rimey
					rimey@arpa.berkeley.edu
					ucbvax!rimey