Re: [Maxima-discuss] complex numbers in Maxima and lisp / a warning?

[Raymond T. <toy...@gm...>]

>>>>> "Richard" == Richard Fateman <fa...@be...> writes:

    Richard> It is possible to construct complex numbers in lisp  (though so far we have
    Richard> mostly avoided it....) . The simplest way is

    Richard> :lisp   (setf $k #c(1 3)

    Richard> now
    Richard> k;  prints as 3 %i+1

I wish maxima didn't do that.  Well, as long as maxima doesn't really
operate with Lisp complex numbers.

    Richard> however,  k -3*%i -1
    Richard> prints as 0 + 3 %i - 3 %i.

    Richard> There are other anomalies, such as

    Richard> ratcoef(k,%i) returns 0.
    Richard> k+1/2 signals an error.
    Richard> sin(k) signals an error

We should probably fix those.  For k+1/2, the error comes from trying
to print k+1/2 which has somehow been computed as ((rat simp) #c(3 6)
2) and printing wants to compare #c(3 6) with 0.

sin(k) fails trying to apply the reflection formula and ends up
comparing (in lisp) #c(-2 -6) and 0.  I have no idea where the #c(-2
-6) comes from.

--
Ray