# series taking too looooooong.

Jens Vollinga vollinga at thep.physik.uni-mainz.de
Mon Apr 19 16:29:03 CEST 2004

```Hello.

On Mon, Apr 19, 2004 at 02:01:35PM +0000, Chris Dams wrote:
>
> Hello,
>
> I found out that if I make the series expansion of a multiplication that
> has somewhere in it a factor to a rather large power (say 8), determining
> the lowest order of that takes very long. For instance, determinging the
> lowest order of
>
> b0^(-10)*(-2*b0^(-7)*log(-b0^(-2)*b1*recs)*b1^3*recs^4-b0^(-5)*log(-b0^(-2)*b1*recs)^2*b1^2*recs^3+b0^(-5)*b1^2*recs^3+b0^(-7)*log(-b0^(-2)*b1*recs)^3*b1^3*recs^4+b0^(-3)*log(-b0^(-2)*b1*recs)*b1*recs^2+3*b0^(-6)*b2*log(-b0^(-2)*b1*recs)*b1*recs^4-1/2*b0^(-7)*b1^3*recs^4-b0^(-4)*b2*recs^3+1/2*b0^(-5)*recs^4*b3-b0^(-1)*recs-b0^(-5)*log(-b0^(-2)*b1*recs)*b1^2*recs^3+5/2*b0^(-7)*log(-b0^(-2)*b1*recs)^2*b1^3*recs^4)^8*b1^9
>
> with respect to the variable recs takes a few seconds on my pentium 1.8
> GHz.
>
> The attached patch should make this much faster by determining the lowest
> order of the base and simply multiplying it with the exponent.

Patch is applied. Thanks!

Bye,
Jens

```