powerseries



On 7/7/07, Barton Willis <willisb at unk.edu> wrote:

> Some of these test failures are due to differences in dummy variables.

No, that's not it -- I put in gensumnum:0 to ensure the same
dummy indices are generated.

Here's the observed vs expected output for the first test which failed.
I believe the only difference is that the expected value has 1 + i1
where the observed has i1 + 1.

/* Problem 14 */
powerseries(1/((1-2*x)*(1-3*x)),x,0);
/* Erroneous Result?:
'sum((3^(i1+1)-2*2^i1)*x^i1,i1,0,inf) */
/* Expected result: */
'sum((3^(1+i1)-2*2^i1)*x^i1,i1,0,inf);

Now the funny thing is that the expected result is actually
written with i1 + 1 in the test script:

powerseries((1)/((1-2*x)*(1-3*x)), x, 0);
'sum((3^(i1+1)-2*2^i1)*x^i1,i1,0,inf);

Why was the expected result changed? Something about
simplification or lack of it?

I've committed the new powerseries code as r1.12 src/series.lisp
and the test cases as r1.24 tests/rtest16.mac.
The series.lisp attached to bug report 1722156 fails to load
because some stuff not related to powerseries has changed
in the meantime.

Thanks for your help,
Robert