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Getting "RuntimeWarning: invalid value encountered in double_scalars" in keplerlib.py

See original GitHub issue

Running the following code:

#!/usr/bin/env python3

import datetime, io, skyfield.api, skyfield.constants, skyfield.data.mpc

print( "Skyfield:", skyfield.__version__ )
latitude = -33
longitude = 151
now = datetime.datetime.strptime( "2020-08-08", "%Y-%m-%d" )
data = "    CK19Y04a  2020 05 31.0420  0.251014  1.001333  177.2464  120.9277   45.8250  20200807  11.6  6.0  C/2019 Y4-A (ATLAS)                                      MPEC 2020-L06"
timeScale = skyfield.api.load.timescale( builtin = True )
topos = skyfield.api.Topos( latitude_degrees = latitude, longitude_degrees = longitude )
ephemeris = skyfield.api.load( "de421.bsp" )
sun = ephemeris[ "sun" ]
earth = ephemeris[ "earth" ]
with io.BytesIO( data.encode() ) as f:
    dataframe = skyfield.data.mpc.load_comets_dataframe( f ).set_index( "designation", drop = False )
    body = sun + skyfield.data.mpc.comet_orbit( dataframe.loc[ "C/2019 Y4-A (ATLAS)" ], timeScale, skyfield.constants.GM_SUN_Pitjeva_2005_km3_s2 )

I am getting the following result:

Skyfield: 1.26
/usr/local/lib/python3.5/dist-packages/skyfield/keplerlib.py:256: RuntimeWarning: invalid value encountered in double_scalars
  return 2 * arctan(((1+e)/(1-e))**.5 * tan(E/2))

I stepped into the function true_anomaly and the parameter E is 0.0…not sure where to go from here!

Issue Analytics

State:
Created 3 years ago
Comments:6 (5 by maintainers)

Top GitHub Comments

2reactions

JoshPatersoncommented, Aug 9, 2020

I’ll be able to take a look at this later tonight!

0reactions

brandon-rhodescommented, Aug 9, 2020

Drat, when I said “re-open” I meant that I was going to press the “Reopen” button right here so we could continue the conversation without your having to open a new issue.

Then?

I closed the tab and entirely forgot to accidentally press “Reopen”.

Thanks for opening the new issue!