[Maxima] ratexpand + pochhammer
willisb at unk.edu
Thu Mar 12 21:37:18 CDT 2009
-----maxima-bounces at math.utexas.edu wrote: -----
>I have used pochhammer a lot to expand special functions for special
>values and in the integration routines for the power functions.
>All this code assumes that pochhammer expands automatically. One problem
>is indeed that there is no upper limit for a useful integer. By the way
>that is a problem with the functions $sum and $product too.
Does this code need things like pochhammer(a,2) --> a (a + 1) or
do you need expressions to be fully expanded: pochhammer(a,2) --> a^2 + a?
Does the code need to expand pochhammer(x,n) when x is both symbolic
>When setting factlim to zero no evaluation of the factorial function is
>done. Setting it no -1 the factorial function does not check the integer
>and tries to evaluate for every integer.
There is an option variable pochhammer_max_index, but it works
differently than does factlim. Setting pochhammer_max_index to -1 keeps
pochhammer(x,n) from expanding:
(%i6) pochhammer(x,1), pochhammer_max_index :-1;
Not so good:
(%i8) pochhammer(x,1), pochhammer_max_index : 'inf;
Maxima encountered a Lisp error:
Error in <= [or a callee]: $INF is not of type (OR RATIONAL LISP:FLOAT).
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