integrating trig functions with large constants, exponent out of range

>>>>> "Neilen" == Neilen Marais <nmarais at sun.ac.za> writes:

    Neilen> Hi
    Neilen> I get the following problem:


    Neilen> (%i8)
    Neilen> integrate(%i*sin((34037595938027*x3)/6154596958582590-(863833069661327*x2)/
    Neilen> 6222711301569210-(863833069661327*x1)/6222711301569210-,
    Neilen> 99614657/338602740)*x3,x3);

    Neilen> Exponent out of range

    Neilen> I tried reducing the error:

    Neilen> (%i9) integrate(%i*sin(34037595938027*x3)*x3, x3);

    Neilen> but had to interrupt it since it seemed to take forever. I found that
    Neilen> the integration time is dependent on the size of the constant in the
    Neilen> expression. integrate(%i*sin((3*x3))*x3, x3) happens fast, 
    Neilen> integrate(%i*sin((30000*x3))*x3, x3) takes several seconds etc.

I can't help with this problem, but the error comes from the fact that
maxima is expecting fixnum arithmetic but the numbers aren't fixnums
for some reason.

The other issue comes from the Risch integrator which is what
integrate uses for simplified integral.  I don't know anything about
how the Risch integrator works.


Ray