astropy: multiple functions from scipy.special do not work with quantities

I just tried to use SciPy’s error function, and Astropy politely requested that I raise this issue here:

>>> from astropy import units
>>> from scipy.special import erf, erfc
>>> r1 = 5*u.m
>>> r2 = 6*u.m
>>> erf(r1/r2)
TypeError: Unknown ufunc erf.  Please raise issue on https://github.com/astropy/astropy
>>> erfc(r1/r2)
TypeError: Unknown ufunc erfc.  Please raise issue on https://github.com/astropy/astropy
>>> erf(r1.value/r2.value)  # workaround
0.76140717068356445

In scipy.special, ufuncs that I would prioritize include:

Error function, etc
Bessel functions
Gamma and related functions
Legendre functions
zeta and zetac - Riemann zeta functions

Thanks!

About this issue

Original URL
State: open
Created 7 years ago
Comments: 23 (22 by maintainers)

Commits related to this issue

Merge pull request #10934 from DiegoAsterio/master More ufuncs work with quantities + test #6390 — committed to astropy/astropy by mhvk 3 years ago

Most upvoted comments

Prospective contributors: take a look at the prioritized list on the first comment and then read https://github.com/astropy/astropy/blob/master/astropy/units/quantity_helper/scipy_special.py

astrojuanlu on Oct 4, 2020

I’m interested, is it still open?

luisval on Mar 30, 2020

What I did to quickly check this was run through all of the non-private functions in scipy.special and see if they worked with 1 * u.dimensionless_unscaled as the sole argument. The list of functions that did not work was very long, but this list would have also included any functions that require two or more arguments and any functions for which 1 is an invalid input.

from astropy import units as u
from scipy import special

dimensionless_quantity = 1 * u.dimensionless_unscaled

for key in sorted(special.__dict__):
    try:
        if key[0] != '_':
            special.__dict__[key](dimensionless_quantity)
    except Exception:
        print(key)

namurphy on May 10, 2019