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Showing posts from August, 2017

Three Sins of Authors

I have been reviewing manuscripts for journal publication. I recently found  Jonathan Shewchuk 's essay  Three Sins of Authors in Computer Science and Math  which sums of much of the "style" feedback I've been giving to authors.

Symbolic Spherical Harmonics

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I have published a Python package that uses SymPy (Symbolic Python) to derive symbolic expressions for the real spherical harmonics in cartesian or spherical coordinates. It is hosted on a  Bitbucket git repository It handles all of the common conventions for normalization and can emit expressions in the syntax of many common programming languages, which is useful for making Ambisonic panners. Here are some examples: bash-3.2$ python symYlm.py --seminormalized --four_pi 1 1 x bash-3.2$ python symYlm.py --seminormalized --four_pi --spherical 1 1 cos(phi)*cos(theta) bash-3.2$ python symYlm.py --seminormalized --four_pi 5 -3 sqrt(70)*(9*z**2 - 1)*(3*x**2*y - y**3)/16 bash-3.2$ python symYlm.py --seminormalized --four_pi -t c 3 2 (1.0L/2.0L)*sqrt(15)*z*(pow(x, 2) - pow(y, 2)) bash-3.2$ python symYlm.py --seminormalized --four_pi 70 -33 15*sqrt(6041436275243981591812583842)*z*(33*x**32*y - 5456*x**30*y**3 + 237336*x**28*y**5 - 4272048*x**26*y**7 + 38567100*x**24*y**9 - 1935367...

The Ambisonic Decoder Toolbox (ADT)

I have published a MATLAB toolbox for designing Ambisonic decoders. It is hosted on  Bitbucket . Many of the papers referenced are available from  my site.