[Maxima] partitioning instead of matching so much

[Barton Willis]

-----maxima-bounces at math.utexas.edu wrote: -----

>I've written up some programs that are largely alternatives to matching.
>I show how the "derivative divides" symbolic integration in Joel Moses'
>SIN program,
one of the initial methods in Maxima's program, can be written in half a
>page or so,

Cool--I changed my abs_integrate to allow a user to append new integration
methods
by appending a function name to a list of integration methods. I hooked up
your
derivative divides code; here is a short demo:

(%i2) load("abs_integrate.mac")$  (not yet in CVS)
(%i4) integrate(a*Ci(x),x);
(%o4) a*(x*Ci(x)-sin(x))

(%i5) integrate(Si(1 - x^2) * x,x);
(%o5) (cos(x^2-1)-(1-x^2)*Si(1-x^2))/2

(%i6) integrate(bessel_j(1, x/42),x);
(%o6) -42*bessel_j(0,x/42)

An option variable extra_integration_methods holds the additional methods
(intfudu is the derivative divides code):

(%i7) extra_integration_methods;
(%o7) [intfudu,signum_int]

(%i8) extra_integration_methods : [];
(%o8) []

(%i9) integrate(bessel_j(1, x/42),x);
(%o9) integrate(bessel_j(1,x/42),x)

Barton