dilog



Hello Sabine,

>  I try to use dilog(). Here is the copy of the error :
>  (%i3) ?dilog(10);
>  Maxima encountered a Lisp error:
>
>   Error in MACSYMA-TOP-LEVEL [or a callee]: 10 is not of type LIST.

The Lisp function DILOG does not calculate numerical
values of the dilogarithm; it is part of the Risch algorithm
for symbolic integration.

li [2] is the symbolic representation of the dilogarithm.
It returns a float value when its argument is a float
or appropriate evaluation flags (namely numer and float) are enabled.

li [2] (10.0);  => .5363012834971784 - 7.233784404149661 %i

li [2] (10);  =>  li[2](10)

%, numer, float;  => .5363012834971784 - 7.233784404149661 %i

Maxima seems to know numerical values of the trilogarithm as well:

li [3] (0.2);  =>  .2053241953742051

li is undocumented -- that is an oversight.

It is possible that there are other representations of the
dilogarithm in Maxima.

Hope this helps,
Robert Dodier