On 2012-08-23, Urs Hackstein <[email protected]> wrote:

> (8*I*e^(I*t) - 24*I)*((e^(I*t) - 3)^7 + (1.52075e+14)*(e^(I*t) - 3)^6 +
> (1.128e+27)*(e^(I*t) - 3)^5 + (1.35375e+38)*(e^(I*t) - 3)^4 -
> (3.127e+50)*(e^(I*t) - 3)^3 - (2.929125e+60)*(e^(I*t) - 3)^2 +
> (9.4875e+72)*e^(I*t) + 3.1375e+73)*e^(I*t)/((e^(I*t) - 3)^8 +
> (1.738e+14)*(e^(I*t) - 3)^7 + (1.504e+27)*(e^(I*t) - 3)^6 +
> (2.166e+38)*(e^(I*t) - 3)^5 - (6.254e+50)*(e^(I*t) - 3)^4 -
> (7.811e+60)*(e^(I*t) - 3)^3 + (3.795e+73)*(e^(I*t) - 3)^2 +
> (4.787e+74)*e^(I*t) - 2.061e+74)
>
> on t\in[0,2*pi], I receive the following error:

> RuntimeError: ECL says: In function GCD, the value of the first argument is
>   1.3545000000021087e74
> which is not of the expected type INTEGER

Sage punts to Maxima to compute integrals symbolically, and Maxima is
trying to factor the integrand or something like that. Maxima generally
prefers exact numbers (integers and ratios of integers) to inexact
(fixed- and variable-precision floats). 

Before trying the integral, can you convert all of the floats to
rational numbers? I don't know how to do that in Sage.

The integrand is a ratio of sums of complex exponentials. I tried a few
variations (the original integrand rationalized, fewer terms, replace
numbers with symbols, replace exp with sin and cos) but Maxima wasn't
able to solve any of them. I don't know what general class of results
one should expect for such an integrand.

The presence of floats suggests (I don't know for sure) that you are
looking for a numerical result. If so, you can try splitting the
integrand into real and imaginary parts, and applying a numerical method
(Sage has Quadpack functions) to each part.

Hope this helps,

Robert Dodier

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