Adding Meta parameter to virgo.plot throws error

[davewyers]

Hi Apostolos

I have noticed that if you include the meta=True parameter to the virgo.plot command it throws an error. Removing the parameter works correctly.

meta (bool) – Display header with date, time, and target

print ('Generate Plot')
virgo.plot(
       obs_parameters=obs,
       n=20,
       m=35,
       f_rest=freq,
       obs_file=prefix+'_observation.dat',
       cal_file='/home/pi/astro/off.dat',
       power_csv=prefix+'_time_series.csv',
       dB=True,
       meta=True,
       spectra_csv=prefix+'_spectrum.csv',
       plot_file=prefix+'_plot.png')

Generate Plot
Traceback (most recent call last):
File "/home/pi/.local/lib/python3.9/site-packages/astropy/coordinates/angle_formats.py", line 302, in parse
found_angle, found_unit = self._thread_local._parser.parse(
File "/home/pi/.local/lib/python3.9/site-packages/astropy/utils/parsing.py", line 115, in parse
return self.parser.parse(*args, **kwargs)
File "/home/pi/.local/lib/python3.9/site-packages/astropy/extern/ply/yacc.py", line 333, in parse
return self.parseopt_notrack(input, lexer, debug, tracking, tokenfunc)
File "/home/pi/.local/lib/python3.9/site-packages/astropy/extern/ply/yacc.py", line 1201, in parseopt_notrack
tok = call_errorfunc(self.errorfunc, errtoken, self)
File "/home/pi/.local/lib/python3.9/site-packages/astropy/extern/ply/yacc.py", line 192, in call_errorfunc
r = errorfunc(token)
File "/home/pi/.local/lib/python3.9/site-packages/astropy/coordinates/angle_formats.py", line 294, in p_error
raise ValueError
ValueError

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "/home/pi/astro/karo2.py", line 119, in
virgo.plot(
File "/home/pi/.local/lib/python3.9/site-packages/virgo/virgo.py", line 710, in plot
obs_location = EarthLocation.from_geodetic(loc[0], loc[1], loc[2])
File "/home/pi/.local/lib/python3.9/site-packages/astropy/coordinates/earth.py", line 297, in from_geodetic
lon = Angle(lon, u.degree, copy=False).wrap_at(180 * u.degree)
File "/home/pi/.local/lib/python3.9/site-packages/astropy/coordinates/angles.py", line 122, in new
angle, angle_unit = form.parse_angle(angle, unit)
File "/home/pi/.local/lib/python3.9/site-packages/astropy/coordinates/angle_formats.py", line 395, in parse_angle
return _AngleParser().parse(angle, unit, debug=debug)
File "/home/pi/.local/lib/python3.9/site-packages/astropy/coordinates/angle_formats.py", line 308, in parse
raise ValueError(
ValueError: Syntax error parsing angle '-'

[0xCoto]

@kevinawilson Could you comment on this? I don't remember much from the meta implementation, but I don't fully understand this particular line of the commit.

Why was if vlsr changed to if vlsr or meta? Isn't that the cause of the error (considering the user did not provide a location)? @davewyers that's just an assumption, please confirm or deny whether the location was indeed not part of the observing parameters (obs_parameters=obs).

[davewyers]

Hi @0xCoto

The Lat and Long are defined in the file then called in the obs object.

Define observation parameters

obs = {
    'dev_args': '',
    'rf_gain': 10,
    'if_gain': 0,
    'bb_gain': 0,
    'frequency': freq,
    'bandwidth': 2.4e6,
    'channels': 2048,
    't_sample': 1,
    'duration': 240,
    'loc': str(lat) + ' ' + str(lon) + ' ' + str(height),
    'ra_dec': str(RA) + ' '+ str(DEC),
    'az_alt': str(az) + ' ' + str(alt)
 }

gal_l, gal_b = virgo.galactic(RA,DEC)
print ('Galactic l = '+str(gal_l))
print ('Galactic b = '+str(gal_b))
virgo.simulate(gal_l, gal_b, beamwidth, -400, 400, prefix+'_simulate.png')

print ('Observe run start')
virgo.observe(obs_parameters=obs, obs_file=prefix+'_observation.dat')
print ('Observe run end')

[prestoeatstacos]

I know this has been out there awhile but appears still an issue with recent, I've had success to change to recommended from EarthLocation changing to for geocentric; lon, lat, height for geodetic). Also note longitude is EAST only so 0 to 360

line 720 change order
original obs_location = EarthLocation.from_geodetic(loc[0], loc[1], loc[2])
change obs_location = EarthLocation.from_geodetic(loc[1], loc[0], loc[2])

line 624 added this global to remove error spam
added global mjd

line 145, 228 change order
original loc = EarthLocation(lat=latu.deg, lon=lonu.deg, height=heightu.m)
changed loc = EarthLocation(lon=lonu.deg, lat=latu.deg, height=heightu.m)

example obs

Define observation parameters

obs = {
'rf_gain': 15,
'if_gain': 5,
'bb_gain': 5,
'dev_args': '',
'frequency': 1420e6,
'bandwidth': 2.4e6,
'channels': 2048,
't_sample': 1,
'duration': 120,
'loc': [32.62, 233.39, 300.00],
'ra_dec': '',
'az_alt': [180, 60],
'spectrometer': 'FTF',
'obs_file': 'firstob.dat6'
}