Bringing out release 0.3.4

[repagh]

I have been looking a bit into getting a windows-also build in conda-forge. To do that cleanly, we need to bring out a new slycot release.

Would it be an option to simply tag v0.3.4, or do we need to merge/fix other issues first?

[moorepants]

@repagh I'm adding you a maintainer on the conda forge feedstock: conda-forge/slycot-feedstock#12

[repagh]

Thanks Jason.
@murrayrm , I propose returning the favour....

Any objections if we merge this? Next week my students are starting control classes, and having slycot in conda-forge would so much simplify the install instructions....

[murrayrm]

No problem on my end. Go for it!

[repagh]

I am a regular member, not maintainer. Turns out I cannot add @moorepants.
And apparently I cannot merge PR #53 either. No merge button. Is that because I have no write access to the Slycot repository, or because I cannot merge my own PR?

[roryyorke]

I've merged the 3 outstanding PRs.

I think conda-forge looks at PyPI for package sources, so we not only need a tag, but a PyPI upload.

I think @repagh should have commit rights---I don't actually know how to check whether or not he does, but from the log I don't see any merges or commits to master made by him, so I guess he doesn't. I also support giving @moorepants commit rights. I don't think I can make changes of this sort.

[repagh]

I have a pull request on the conda-forge feedstock for this. That one temporarily used the branch from my repository to get the source, but I intend to change that to use source from the python-control github repository, using a tagged release, rather than making a detour over PyPi; In that way it is immediately clear where the source is coming from.

[repagh]

This means that I still need a tag (v0.3.4) to complete the feedstock.

[roryyorke]

OK, great. The remaining hold-up is release notes, see e.g. https://github.com/python-control/Slycot/releases/tag/v0.3.3. I'll try to do that this weekend; will post draft notes here.

I assume we'll still eventually upload a source tarball to PyPI?

[moorepants]

I recommend releasing to PyPI and having conda forge pull from there. It helps to ensure people can actually install and build from the PyPi release being that the github tarball and the pypi tarballs are different.

[moorepants]

Also, the conda forge infrastructure checks pypi for updated packages and automatically create's PRs on the feedstock when pypi updates.

[roryyorke]

proposed release notes below. I'm not very familiar with the system pencil terminology, please let me know if what i've written is nonsense.

title: 0.3.4: added ag08bd, sb10jd, tg01ad, and tg01fd; switched to scikit-build.

New features

Support for four SLICOT routines was added by Marcus Liljedahl.

ag08bd Process system pencil to find multivariable zeros

ag08bd takes a system pencil (E,A,B,C,D) and returns a matrix pair (Af, Ef) which can be used to find the finite multivariable ("Smith") zeros. The orders of infinite zeros, right and left Kronecker indices, and multiplicities of infinite eigenvalues are also returned.

sb10jd Convert descriptor to non-descriptor form

sb10jd converts a descriptor state-space system (E,A,B,C,D) to a regular state-space system (Ad, Bd, Cd, Dd).

tg01ad Balance system pencil

tg01ad balances system pencils (E,A,B,C,D), with D=0, such that the rows and columns of the resulting pencil are as close in norm as possible.

tg01fd SVD-like coordinate form of system pencil

tg01fd finds the orthogonal transformation matrices for a system pencil (E,A,B,C,D), with D=0, such that the result is in SVD-like coordinate form.

Build

Rene van Paassen switched the build over to scikit-build, which allows for flang to be used to build SLICOT on Windows, and improves the build output for developers.

Testing

Python 3.7 was added to the Travis CI build set.

The tests no longer use the deprecated np.matrix type.

Added a regression test for #6, for td04ad.

Pull requests and issues associated with the release

PRs merged: #32, #34, #36, #38, #43, #45, #51, #52, #53, #56, #57
Issues fixed: #35, #37, #47, #55
Issues closed ("wont-fix"): #40, #41, #48

[repagh]

Looks good. Then again, I mostly use physical pencils....
The switch to scikit was a means to get additional flexibility in selecting build tools, the switch to flang is a result from that.

[roryyorke]

0.3.4 released

[roryyorke]

I'm afraid I didn't realize there was a bit more to releasing; it looks like setup.py must be edited. I've deleted v0.3.4 for now.

I assume the idea is to have a release branch.