common lisp complex numbers, also common lisp rational numbers
Subject: common lisp complex numbers, also common lisp rational numbers
From: Stavros Macrakis
Date: Thu, 1 Mar 2012 13:20:51 -0500
I wouldn't say that "the intermixing of Maxima rationals and CL rationals
has bugs", but simply that "CL rationals and complexes are not supported as
part of Maxima expressions". As far as I know, there has been no
systematic effort to change this.
-s
On Thu, Mar 1, 2012 at 13:17, Richard Fateman <fateman at eecs.berkeley.edu>wrote:
> sometimes these may come up, from lisp routines. Or you can create them
> in maxima
> this way:
>
> A: ?complex(1,2)
>
> Should numberp(A) return true? (it doesn't).
>
> It is certainly a tricky situation to deal with, generally... should
> a complex constant like 1+2*%i be stored in common lisp as #c(1 2)...
> which has various positive aspects, mostly having to do with numerics.
>
> but has the negative aspects that
>
> 1. the re and im parts must be lisp number constants and that excludes
> bigfloats.
> 2. it also excludes symbolic re and im parts.
>
> I think numberp(A) should return true if ?numberp(A) returns true [it
> does]..
> that is, every common lisp number should be a number to Maxima as well.
>
> Oh, CL rational numbers might also be allowed as Maxima numbers too.
>
> Here's a confusing situation...
>
> :lisp (setf $aa 1/2)
>
> aa+1/3
>
> returns 5/2/3
>
> So the intermixing of Maxima rationals and CL rationals has bugs.
> But we knew this.
>
> RJF
>
>
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