[SciPy-Dev] Spherical harmonics, convention

Matthew Brett matthew.brett@gmail....
Fri Mar 19 12:50:22 CDT 2010


Hi,

I noticed that scipy.special.sph_harm uses conventions that (on
superficial reading) seem to be rather unusual; can I ask for advice
whether that is correct?

For example; http://en.wikipedia.org/wiki/Spherical_harmonics assumes:

theta = polar angle
phi = azimuthal angle
l (little L) = degree of harmonic

but we have:

theta = azimuthal angle
phi = polar angle
n = degree of harmonic

I realize that the theta / phi switch is the difference between
physics and math conventions of spherical coordinates, but my
superficial impression was that there was a rather strong tradition in
spherical harmonics to prefer theta = polar, phi = azimuthal; is that
correct?

Thanks a lot,

Matthew


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