Ilya Zakharevich on Mon, 25 Sep 2000 15:36:57 -0400 |
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Re: power series bug |
On Mon, Sep 25, 2000 at 02:18:30PM -0400, Igor Schein wrote: > ? (acos(y)+z)^1.; > *** Warning: normalizing a polynomial with 0 leading term. > *** Warning: normalizing a series with 0 leading term. > *** division by zero in gdiv, gdivgs or ginv > > If I pre-introduce variable z to the stack, it works fine: > > ? z^2;(acos(y)+z)^1.; > ? This is easy, even I can answer it: to take a fractional power of a series, you need to have the leading term of degree 0 - and with a coefficient you can take a power of. The leading term of the second one is acos(y)*z^0 (it is a series in z), the leading term of the first one is z*y^0 (it is a series in y). Applying the same argument, it makes sense to take a power of acos(y), but not of z. Ilya