Problems with order parameter of 'series' method

Chris Dams chrisd at
Tue Feb 17 19:52:51 CET 2004

Hello Jens,

On Tue, 17 Feb 2004, Jens Vollinga wrote:

> The series expansion in GiNaC has now been revised in favor of
> a more predictable expansion scheme. The given order parameter
> now determines the last exact term in the series.

In principle this is good, but I think it is a very bad idea to let the
order give the last exact term in the series. I think order-1 should be
equal to the last exact term. The reason is that this is more compatible
with what we are used to. I don't think you want to force your users to

f.series(x, version_micro>whatever ? order-1 : order),

do you? Calculating an expression to an order that is one higher than is
usefull, can easily result in a program taking an order of magnitude
longer to finish.

Also I found some bugs. I will report them as soon as is clear what series
is supposed to do.


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