On 11-Jan-2008, Ben Abbott wrote:
| I believe this patch is ready to be committed.
|
| In the event of pole multiplicity, the committed version of
residue.m
| does not use a single pole to represent a group of multiplicity.
| Instead the expansion of residues is done with the poles returned by
| roots . The attached patch changes the pole value associated with a
| group of multiplicity to be that of the mean of then entire group.
|
| For example, if the poles were given by
|
| octave:1> p = [3 3 3 3 3];
| octave:2> p = roots(poly(p))
| p =
|
| 3.0026 + 0.0000i
| 3.0008 + 0.0024i
| 3.0008 - 0.0024i
| 2.9979 + 0.0015i
| 2.9979 - 0.0015i
|
| The current committed version expands to residues as
|
| r(1)/(x-p(1)) + r(2)/(x-p(2)).^2 + r(3)/(x-p(3)).^3 + r(4)/(x-
p(4)).^4
| + r(5)/(x-p(5)).^5
|
| With each element of p(:) being different. However, the expansion of
| residues should use a single value for the poles of a multiplicity
| group.
|
| octave:3> p = mean(p)*ones(size(p))
| p =
|
| 3.0000
| 3.0000
| 3.0000
| 3.0000
| 3.0000
|
| This patch makes this change.
|
| In addition the checks for poles of zero value, pure real values,
and
| pure imaginary values is done *after* consideration of pole
| multiplicity.
|
| The attached patch and ChangeLog are identical to that submitted on
| Dec 31.
OK, sorry for the delay. I checked this in to CVS head and the 3.0
branch.
Thanks,
jwe