[GiNaC-list] That series again
Ralf Stephan
ralf at ark.in-berlin.de
Fri Aug 13 19:41:04 CEST 2004
Using the new 1.2.3, in ginsh:
> series((1+x)^y,x,5);
1+Order(x^5)
while
> series(exp(y*log(1+x)),x,5);
1+(y)*x+(-1/2*y+1/2*y^2)*x^2+(1/3*y-1/2*y^2+1/6*y^3)*x^3+(1/24*y^4-1/4*y+11/24*y^2-1/4*y^3)*x^4+Order(x^5)
My understanding is the latter is correct as it gives 1/n! the Stirling1
triangle and substituting a number for y gives binomial coefficients.
Maybe any expansion of a power can be expressed by such a construction,
even in the GiNaC source, so a patch would be straightforward?
ralf
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