On 7/24/09, David Webb <djw at soton.ac.uk> wrote:
> (%i3) G : diff(a(x,z),x,1);
> d
> (%o3) -- (a(x, z))
> dx
> (%i4) H : taylor(G,z,0,1);
> d
> (%o4)/T/ -- (a(x, z)) + . . .
> dx
Agreed, it's a bug. Thanks for bringing it to our attention.
Can you please make a bug report so we don't lose track of it?
https://sourceforge.net/tracker/?func=add&group_id=4933&atid=104933
Here is another work-around ...
H : taylor (b (x, z), z, 0, 1);
=> b(x,0)+('at('diff(b(x,z),z,1),z = 0))*z
b (x, z) := 'diff (a (x, z), x, 1);
ev (H);
=> ('at('diff(a(x,z),x,1,z,1),z = 0))*z+'diff(a(x,0),x,1)
That's right, isn't it?
On an unrelated note, I don't like the "at" notation, a prejudice I
adopted from my favorite math prof back in the day ...
Getting rid of it probably requires that stuff like diff should
work on functions, not expressions. Something to think about
on a rainy day.
Hope all is well, & thanks for your interest in Maxima.
Robert Dodier