But, if it's somehow helpful, here's my example from the beginning:

>>> import astropy.units as u
>>> import sunpy.map
>>> from sunpy.data.sample import HMI_LOS_IMAGE
>>> hmi_map = sunpy.map.Map(HMI_LOS_IMAGE)
>>> arcsec_coord = hmi_map.pixel_to_world(600*u.pix, 300*u.pix)
>>> print(arcsec_coord)
<SkyCoord (Helioprojective: obstime=2011-06-07T06:32:11.000, rsun=696000.0 km, observer=<HeliographicStonyhurst Coordinate (obstime=2011-06-07T06:32:11.000, rsun=696000.0 km): (lon, lat, radius) in (deg, deg, m)
    (0.07430567, 0.048537, 1.51846024e+11)>): (Tx, Ty) in arcsec
    (-182.22906643, 426.71390943)>
>>> print(arcsec_coord.heliographic_stonyhurst)
<SkyCoord (HeliographicStonyhurst: obstime=2011-06-07T06:32:11.000, rsun=696000.0 km): (lon, lat, radius) in (deg, deg, m)
    (-12.34153662, 26.76145867, 6.96e+08)>

I'm trying to plot the PFSS solution for that date but I'm getting this error about a missing key. Here's the code and the error below:

import numpy as np
import pfsspy
from pfsspy import coords, tracing
import sunpy.map
from sunpy.net import Fido, attrs as a
import astropy.units as u
import astropy.constants as const
from astropy.coordinates import SkyCoord


gong_result = Fido.search(a.Time('2021-09-18 12:00:00', '2021-09-18 13:00:00'), a.Instrument('GONG'))
gong = Fido.fetch(gong_result, path='./{instrument}/{file}')
gong_map = sunpy.map.Map(gong)

nrho = 35
rss = 2.5
pfss_in = pfsspy.Input(gong_map, nrho, rss)
pfss_out = pfsspy.pfss(pfss_in)

num_footpoints_lat = 40
num_footpoints_lon = 60
lat = np.linspace(np.radians(-75), np.radians(75), num_footpoints_lat, endpoint=False)
lon = np.linspace(np.radians(0), np.radians(365), num_footpoints_lon, endpoint=False)

lat, lon = np.meshgrid(lat, lon, indexing='ij')
lat, lon = lat.ravel()*u.rad, lon.ravel()*u.rad
r = 1.2*const.R_sun

seeds = SkyCoord(lon, lat, r, frame=pfss_out.coordinate_frame)
tracer = tracing.FortranTracer()
flines = tracer.trace(seeds, pfss_out)

Files Downloaded:   0%|          | 0/1 [00:00<?, ?file/s]
INFO: Missing metadata for solar radius: assuming the standard radius of the photosphere. [sunpy.map.mapbase]
---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
Cell In[3], line 31
     29 seeds = SkyCoord(lon, lat, r, frame=pfss_out.coordinate_frame)
     30 tracer = tracing.FortranTracer()
---> 31 flines = tracer.trace(seeds, pfss_out)

File ~/.conda/envs/solo8/lib/python3.9/site-packages/pfsspy/tracing.py:151, in FortranTracer.trace(self, seeds, output)
    148     self.tracer.max_steps = int(4 * output.grid.nr / self.step_size)
    150 self.validate_seeds(seeds)
--> 151 x, y, z = self.coords_to_xyz(seeds, output)
    152 r, lat, phi = astrocoords.cartesian_to_spherical(x, y, z)
    154 # Force 360deg wrapping

File ~/.conda/envs/solo8/lib/python3.9/site-packages/pfsspy/tracing.py:66, in Tracer.coords_to_xyz(seeds, output)
     63 lon = seeds.lon
     64 # Note we want 0deg longitude to be a point on the LH side of the map,
     65 # but _lon0 is center of map, so offset by 180deg
---> 66 lon -= output._lon0 - 180 * u.deg
     67 x, y, z = astrocoords.spherical_to_cartesian(
     68     seeds.radius, seeds.lat, lon)
     69 x = x.to_value(const.R_sun)

File ~/.conda/envs/solo8/lib/python3.9/site-packages/pfsspy/output.py:58, in Output._lon0(self)
     54 @property
     55 def _lon0(self):
     56     """Longitude offset of the map."""
     57     return (self.input_map.meta['crval1'] *
---> 58             u.Unit(self.input_map.meta['cunit1']))

File ~/.conda/envs/solo8/lib/python3.9/site-packages/sunpy/util/metadata.py:167, in MetaDict.__getitem__(self, key)
    163 def __getitem__(self, key):
    164     """
    165     Override ``[]`` indexing.
    166     """
--> 167     return OrderedDict.__getitem__(self, key.lower())

KeyError: 'cunit1'

I tested it with different dates and times and I still get the same error.

sunpy: 5.1.2
pfsspy: 1.2.0
python 3.9.13

I'm trying to plot the PFSS solution for that date but I'm getting this error about a missing key. Here's the code and the error below:

import numpy as np
import pfsspy
from pfsspy import coords, tracing
import sunpy.map
from sunpy.net import Fido, attrs as a
import astropy.units as u
import astropy.constants as const
from astropy.coordinates import SkyCoord


gong_result = Fido.search(a.Time('2021-09-18 12:00:00', '2021-09-18 13:00:00'), a.Instrument('GONG'))
gong = Fido.fetch(gong_result, path='./{instrument}/{file}')
gong_map = sunpy.map.Map(gong)

nrho = 35
rss = 2.5
pfss_in = pfsspy.Input(gong_map, nrho, rss)
pfss_out = pfsspy.pfss(pfss_in)

num_footpoints_lat = 40
num_footpoints_lon = 60
lat = np.linspace(np.radians(-75), np.radians(75), num_footpoints_lat, endpoint=False)
lon = np.linspace(np.radians(0), np.radians(365), num_footpoints_lon, endpoint=False)

lat, lon = np.meshgrid(lat, lon, indexing='ij')
lat, lon = lat.ravel()*u.rad, lon.ravel()*u.rad
r = 1.2*const.R_sun

seeds = SkyCoord(lon, lat, r, frame=pfss_out.coordinate_frame)
tracer = tracing.FortranTracer()
flines = tracer.trace(seeds, pfss_out)

Files Downloaded:   0%|          | 0/1 [00:00<?, ?file/s]
INFO: Missing metadata for solar radius: assuming the standard radius of the photosphere. [sunpy.map.mapbase]
---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
Cell In[3], line 31
     29 seeds = SkyCoord(lon, lat, r, frame=pfss_out.coordinate_frame)
     30 tracer = tracing.FortranTracer()
---> 31 flines = tracer.trace(seeds, pfss_out)

File ~/.conda/envs/solo8/lib/python3.9/site-packages/pfsspy/tracing.py:151, in FortranTracer.trace(self, seeds, output)
    148     self.tracer.max_steps = int(4 * output.grid.nr / self.step_size)
    150 self.validate_seeds(seeds)
--> 151 x, y, z = self.coords_to_xyz(seeds, output)
    152 r, lat, phi = astrocoords.cartesian_to_spherical(x, y, z)
    154 # Force 360deg wrapping

File ~/.conda/envs/solo8/lib/python3.9/site-packages/pfsspy/tracing.py:66, in Tracer.coords_to_xyz(seeds, output)
     63 lon = seeds.lon
     64 # Note we want 0deg longitude to be a point on the LH side of the map,
     65 # but _lon0 is center of map, so offset by 180deg
---> 66 lon -= output._lon0 - 180 * u.deg
     67 x, y, z = astrocoords.spherical_to_cartesian(
     68     seeds.radius, seeds.lat, lon)
     69 x = x.to_value(const.R_sun)

File ~/.conda/envs/solo8/lib/python3.9/site-packages/pfsspy/output.py:58, in Output._lon0(self)
     54 @property
     55 def _lon0(self):
     56     """Longitude offset of the map."""
     57     return (self.input_map.meta['crval1'] *
---> 58             u.Unit(self.input_map.meta['cunit1']))

File ~/.conda/envs/solo8/lib/python3.9/site-packages/sunpy/util/metadata.py:167, in MetaDict.__getitem__(self, key)
    163 def __getitem__(self, key):
    164     """
    165     Override ``[]`` indexing.
    166     """
--> 167     return OrderedDict.__getitem__(self, key.lower())

KeyError: 'cunit1'

I tested it with different dates and times and I still get the same error. Is there a way to fix it?

sunpy: 5.1.2
pfsspy: 1.2.0
python 3.9.13

In reply to @ayshih:matrix.org

But, if it's somehow helpful, here's my example from the beginning:

>>> import astropy.units as u
>>> import sunpy.map
>>> from sunpy.data.sample import HMI_LOS_IMAGE
>>> hmi_map = sunpy.map.Map(HMI_LOS_IMAGE)
>>> arcsec_coord = hmi_map.pixel_to_world(600*u.pix, 300*u.pix)
>>> print(arcsec_coord)
<SkyCoord (Helioprojective: obstime=2011-06-07T06:32:11.000, rsun=696000.0 km, observer=<HeliographicStonyhurst Coordinate (obstime=2011-06-07T06:32:11.000, rsun=696000.0 km): (lon, lat, radius) in (deg, deg, m)
    (0.07430567, 0.048537, 1.51846024e+11)>): (Tx, Ty) in arcsec
    (-182.22906643, 426.71390943)>
>>> print(arcsec_coord.heliographic_stonyhurst)
<SkyCoord (HeliographicStonyhurst: obstime=2011-06-07T06:32:11.000, rsun=696000.0 km): (lon, lat, radius) in (deg, deg, m)
    (-12.34153662, 26.76145867, 6.96e+08)>

In reply to @fresnels:matrix.org
Thanks! Now I understand it better. One more question, in line 10. where can I get the list for available keywords like the .heliographic_stonyhurst that is used here. It looks slightly different from sunpy.coordinates.frames

In reply to @mohamednedal:matrix.org

I'm trying to plot the PFSS solution for that date but I'm getting this error about a missing key. Here's the code and the error below:

import numpy as np
import pfsspy
from pfsspy import coords, tracing
import sunpy.map
from sunpy.net import Fido, attrs as a
import astropy.units as u
import astropy.constants as const
from astropy.coordinates import SkyCoord


gong_result = Fido.search(a.Time('2021-09-18 12:00:00', '2021-09-18 13:00:00'), a.Instrument('GONG'))
gong = Fido.fetch(gong_result, path='./{instrument}/{file}')
gong_map = sunpy.map.Map(gong)

nrho = 35
rss = 2.5
pfss_in = pfsspy.Input(gong_map, nrho, rss)
pfss_out = pfsspy.pfss(pfss_in)

num_footpoints_lat = 40
num_footpoints_lon = 60
lat = np.linspace(np.radians(-75), np.radians(75), num_footpoints_lat, endpoint=False)
lon = np.linspace(np.radians(0), np.radians(365), num_footpoints_lon, endpoint=False)

lat, lon = np.meshgrid(lat, lon, indexing='ij')
lat, lon = lat.ravel()*u.rad, lon.ravel()*u.rad
r = 1.2*const.R_sun

seeds = SkyCoord(lon, lat, r, frame=pfss_out.coordinate_frame)
tracer = tracing.FortranTracer()
flines = tracer.trace(seeds, pfss_out)

Files Downloaded:   0%|          | 0/1 [00:00<?, ?file/s]
INFO: Missing metadata for solar radius: assuming the standard radius of the photosphere. [sunpy.map.mapbase]
---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
Cell In[3], line 31
     29 seeds = SkyCoord(lon, lat, r, frame=pfss_out.coordinate_frame)
     30 tracer = tracing.FortranTracer()
---> 31 flines = tracer.trace(seeds, pfss_out)

File ~/.conda/envs/solo8/lib/python3.9/site-packages/pfsspy/tracing.py:151, in FortranTracer.trace(self, seeds, output)
    148     self.tracer.max_steps = int(4 * output.grid.nr / self.step_size)
    150 self.validate_seeds(seeds)
--> 151 x, y, z = self.coords_to_xyz(seeds, output)
    152 r, lat, phi = astrocoords.cartesian_to_spherical(x, y, z)
    154 # Force 360deg wrapping

File ~/.conda/envs/solo8/lib/python3.9/site-packages/pfsspy/tracing.py:66, in Tracer.coords_to_xyz(seeds, output)
     63 lon = seeds.lon
     64 # Note we want 0deg longitude to be a point on the LH side of the map,
     65 # but _lon0 is center of map, so offset by 180deg
---> 66 lon -= output._lon0 - 180 * u.deg
     67 x, y, z = astrocoords.spherical_to_cartesian(
     68     seeds.radius, seeds.lat, lon)
     69 x = x.to_value(const.R_sun)

File ~/.conda/envs/solo8/lib/python3.9/site-packages/pfsspy/output.py:58, in Output._lon0(self)
     54 @property
     55 def _lon0(self):
     56     """Longitude offset of the map."""
     57     return (self.input_map.meta['crval1'] *
---> 58             u.Unit(self.input_map.meta['cunit1']))

File ~/.conda/envs/solo8/lib/python3.9/site-packages/sunpy/util/metadata.py:167, in MetaDict.__getitem__(self, key)
    163 def __getitem__(self, key):
    164     """
    165     Override ``[]`` indexing.
    166     """
--> 167     return OrderedDict.__getitem__(self, key.lower())

KeyError: 'cunit1'

I tested it with different dates and times and I still get the same error. Is there a way to fix it?

sunpy: 5.1.2
pfsspy: 1.2.0
python 3.9.13

In reply to @Nabobalis:matrix.org
pfsspy is no longer maintained and we broke it with some changes in sunpy 5.1, the sunpy project is spinning up a replacement https://github.com/sunpy/sunkit-magex, Cadair what is the status of that?

I tried to install sunkit-magex from this website in a virtual environment and I got this error message:

ERROR: Could not find a version that satisfies the requirement sunkit-magex (from versions: none)                                                                                                                  ERROR: No matching distribution found for sunkit-magex

In reply to @Nabobalis:matrix.org
pfsspy is no longer maintained and we broke it with some changes in sunpy 5.1, the sunpy project is spinning up a replacement https://github.com/sunpy/sunkit-magex, Cadair what is the status of that?

I tried to install sunkit-magex from this website in a virtual environment and I got this error message:

ERROR: Could not find a version that satisfies the requirement sunkit-magex (from versions: none)

ERROR: No matching distribution found for sunkit-magex

In reply to @alasdairwilson:matrix.org
You can install from the git repo though

In reply to @alasdairwilson:matrix.org
Just download the .exe... I mean "pip install git+urlofrepo" or clone the repo and do "pip install -e ." In the folder.