Mailman 3 September 2017 - SciPy-Dev

Debugging a segfault
by Andrew Nelson Sept. 14, 2017

Sept. 14, 2017

I'm using a computing cluster which has no access to the outside world, which means I have had to install everything from source, including Python. I've built scipy and am trying to run the test suite. However, python is crashing somewhere in `io/tests/test_fortran.py`. I tried to run the module in gdb and got the following: https://gist.github.com/andyfaff/18d3e8ee8551c630316afd66591f4cb7 I would try to investigate further but I don't know how to proceed.

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Clarkson Woodruff Transform implementation (Randomized Numerical Linear Algebra)
by Jordi Montes Sept. 13, 2017

Sept. 13, 2017

Hello, I just made a pull request to the official repository with the implementation of the Clarkson Woodruff Transform (Count Min Sketch) for dense matrices. You can find more details of the pull request here <https://github.com/scipy/scipy/pull/7809>. I would not like to made it badly (this is my pull request to the project) so any advice is welcome (Main implementation/tests/documentation). Jordi Montes.

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Need to filter DeprecationWarnings in the tests?
by Warren Weckesser Sept. 8, 2017

Sept. 8, 2017

In the original version of a pull request that I am updating ( https://github.com/scipy/scipy/pull/7190), I had filtered DeprecationWarnings in the unit tests. Now that we are using pytest, is this still necessary? According to https://docs.pytest.org/en/latest/warnings.html, by default, pytest doesn't report DeprecatingWarnings, so it looks like there is no need to filter them with `numpy.tests.suppress_warnings()`. Is that correct? Warren

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Proposed API change for some functions in scipy.signal
by Warren Weckesser Sept. 2, 2017

Sept. 2, 2017

I've been using quite a few of the functions in scipy.signal recently, and I've been reminded of some of the quirks of the API. I have submitted a pull request to clean up one of those quirks. In the new pull request, I have added the argument 'fs' (the sampling frequency) to the following functions: firwin, firwin2, firls, and remez. For firwin, firwin2 and firls, the new argument replaces 'nyq', and for remez, it replaces 'Hz'. This makes these functions consistent with the other functions in which the sampling frequency is specified using 'fs': periodogram, welch, csd, coherence, spectrogram, stft, and istft. 'fs', or in LaTeX, $f_s$, is common notation for the sampling frequency in the DSP literature. In the pull request, the old argument is given a "soft" deprecation. That means the docstring says the argument is deprecated, but code to actually generate a DeprecationWarning has not been added yet. I'm fine with adding that now, but some might prefer a relatively long and soft transition for these changes. (Personally, I don't mind if they hang around for a while, but they should be gone by 2.0. :) I haven't changed the default value of the sampling frequency. For the FIR filter design functions firls, firwin and firwin2, the default is nyq=1.0 (equivalent to fs=2), while for remez the default is Hz=1 (i.e. fs=1). The functions that currently already use 'fs' all have the default fs=1. Changing the default for the FIR design functions would be a much more disruptive change. Comments here or on the pull request are welcome. P.S. I can see future pull requests in which 'fs' is added to functions that currently don't have an argument to specify the sampling frequency. I'm looking at you, freqz.

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N dimensional Gaussian quadrature
by oss Sept. 2, 2017

Sept. 2, 2017

Hi scipy-dev, We ve implemented and tested n dimensional fixed_quad function with choice of orders for each dimension separately (useful when known singular points need to be avoided). See the diff below. We re open for any request for improvement. https://github.com/scipy/scipy/compare/master...multiwave:n_fixed_quad <https://github.com/scipy/scipy/compare/master...multiwave:n_fixed_quad> Thanks tryfon@multiwave

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SPMV not implemented in linalg.blas?
by marc Sept. 2, 2017

Sept. 2, 2017

Dear Scipy developers, Do there is a particular reason why the Blas routine SPMV does not have a wrapper in Scipy? Marc

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