Revert "Merge remote-tracking branch 'upstream/image_sim' into improv…

…e-pytest-#26"

This reverts commit 308168f.

docs/index.rst

@@ -129,7 +129,6 @@ Reference/API
   :skip: SkyCoord
   :skip: CCDData
   :skip: interp1d
-  :skip: InvalidTransformError
   :no-inheritance-diagram:
 
 .. automodapi:: gunagala.optic

gunagala/imager.py

@@ -13,7 +13,7 @@
 
 from astropy import constants as c
 from astropy import units as u
-from astropy.wcs import WCS, InvalidTransformError
+from astropy.wcs import WCS
 from astropy.coordinates import SkyCoord
 from astropy.nddata import CCDData
 
@@ -254,7 +254,6 @@ def __init__(self, optic, camera, filters, psf, sky, num_imagers=1, num_per_comp
         self.wcs.wcs.cdelt = [self.pixel_scale.to(u.degree / u.pixel).value,
                               self.pixel_scale.to(u.degree / u.pixel).value]
         self.wcs.wcs.ctype = ['RA---TAN', 'DEC--TAN']
-        self.wcs.wcs.crval = [None, None]
 
         # Calculate end to end efficiencies, etc.
         self._efficiencies()
@@ -284,29 +283,6 @@ def __init__(self, optic, camera, filters, psf, sky, num_imagers=1, num_per_comp
                 # Not a callable, should be a Simple sky model which just returns AB magnitudes per square arcsecond
                 self.sky_rate[filter_name] = self.SB_to_rate(sb, filter_name)
 
-
-    def set_WCS_centre(self, centre, *args, **kwargs):
-        """
-        Set the WCS CRVALs of the Imager instance to centre.
-
-        Parameters
-        ----------
-        centre : astropy.coordinates.SkyCoord or str
-            Sky coordinates of the image centre. Must be either a SkyCoord object or convertible
-            to one by the constructor of SkyCoord.
-        unit : str (optional)
-            Unit is the same as for the astropy.coordinates.SkyCoord(), e.g.
-            SkyCoord(RAdec[0], RAdec[1], unit='deg')
-        """
-
-        # Ensure centre is a SkyCoord (this allows entering centre as a string)
-        if not isinstance(centre, SkyCoord):
-            centre = SkyCoord(centre, **kwargs)
-
-        # Set field centre coordinates in internal WCS
-        self.wcs.wcs.crval = [centre.icrs.ra.value, centre.icrs.dec.value]
-
-
     def extended_source_signal_noise(self, surface_brightness, filter_name, total_exp_time, sub_exp_time,
                                      calc_type='per pixel', saturation_check=True, binning=1):
         """
@@ -1535,52 +1511,48 @@ def snr_vs_ABmag(self, exp_times, filter_name, magnitude_interval=0.02 * u.ABmag
 
         return magnitudes.to(u.ABmag), snrs.to(u.dimensionless_unscaled)
 
-    def get_pixel_coords(self):
+    def get_pixel_coords(self, centre):
         """
         Utility function to return a SkyCoord array containing the on sky position
-        of the centre of all the pixels in the image.
+        of the centre of all the pixels in the image, given a SkyCoord for the
+        field centre
         """
+        # Ensure centre is a SkyCoord (this allows entering centre as a string)
+        if not isinstance(centre, SkyCoord):
+            centre = SkyCoord(centre)
+
+        # Set field centre coordinates in internal WCS
+        self.wcs.wcs.crval = [centre.icrs.ra.value, centre.icrs.dec.value]
+
         # Arrays of pixel coordinates
         XY = np.meshgrid(np.arange(self.wcs._naxis1), np.arange(self.wcs._naxis2))
 
         # Convert to arrays of RA, dec (ICRS, decimal degrees)
-        try:
-            RAdec = self.wcs.all_pix2world(XY[0], XY[1], 0)
-        except InvalidTransformError:
-            raise ValueError("CRVAL not set! Must call set_WCS_centre before get_pixel_coords")
+        RAdec = self.wcs.all_pix2world(XY[0], XY[1], 0)
 
         return SkyCoord(RAdec[0], RAdec[1], unit='deg')
 
     def make_noiseless_image(self,
                              centre,
                              obs_time,
                              filter_name,
-                             centre_kwargs={},
-                             stars=None,
-                             star_kwargs={}):
+                             stars=None):
         """
-        Creates a noiseless simulated image for a given image centre and
-        observation time.
+        Creates a noiseless simulated image for a given image centre and observation time.
 
         Parameters
         ----------
         centre : astropy.coordinates.SkyCoord or str
-            Sky coordinates of the image centre. Must be either a SkyCoord
-            object or convertible to one by the constructor of SkyCoord.
+            Sky coordinates of the image centre. Must be either a SkyCoord object or convertible
+            to one by the constructor of SkyCoord.
         obs_time : astropy.time.Time or str
-            Time of the obseration. This can be relevant when calculating the
-            sky background and source positions. Must be either a Time object
-            or convertible to one by the constructor of Time.
+            Time of the obseration. This can be relevant when calculating the sky background
+            and source positions. Must be either a Time object or convertible to one by the
+            constructor of Time.
         filter_name : str
             Name of the optical filter to use.
         stars : sequence, optional
             Sequence containing
-        centre_kwargs : dict (optional)
-            kwargs for centre kwargs to send to astropy.coordinates.SkyCoord(),
-            e.g. SkyCoord(centre, unit='deg')
-        star_kwargs : dict (optional)
-            kwargs for star kwargs to send to astropy.coordinates.SkyCoord(),
-            e.g. SkyCoord(coords, unit='deg')
 
         Returns
         -------
@@ -1589,19 +1561,18 @@ def make_noiseless_image(self,
         """
         electrons = np.zeros((self.wcs._naxis2,
                               self.wcs._naxis1)) * u.electron / (u.second * u.pixel)
-        self.set_WCS_centre(centre, **centre_kwargs)
 
         # Calculate observed sky background
         sky_rate = self.sky_rate[filter_name]
         if hasattr(self.sky, 'relative_brightness'):
-            pixel_coords = self.get_pixel_coords()
+            pixel_coords = self.get_pixel_coords(centre)
             relative_sky = self.sky.relative_brightness(pixel_coords, obs_time)
             sky_rate = sky_rate * relative_sky
         electrons = electrons + sky_rate
 
         if stars is not None:
             for (coords, magnitude) in stars:
-                coords = SkyCoord(coords, **star_kwargs)
+                coords = SkyCoord(coords)
                 pixel_coords = self.wcs.all_world2pix(((coords.ra.degree, coords.dec.degree),), 0) \
                     - self.wcs.wcs.crpix
                 star_rate = self.ABmag_to_rate(magnitude, filter_name)

gunagala/tests/test_imager.py

@@ -3,7 +3,6 @@
 import numpy as np
 import astropy.units as u
 import astropy.constants as c
-from astropy.coordinates import SkyCoord
 
 from gunagala.optic import Optic
 from gunagala.optical_filter import Filter
@@ -78,12 +77,6 @@ def imager(lens, ccd, filters, psf, sky):
     return imager
 
 
-@pytest.fixture(scope='function')
-def imager_function_scope(lens, ccd, filters, psf, sky):
-    imager = Imager(optic=lens, camera=ccd, filters=filters, psf=psf, sky=sky, num_imagers=5, num_per_computer=5)
-    return imager
-
-
 def test_init(imager):
     assert isinstance(imager, Imager)
     assert imager.pixel_scale == (5.4 * u.micron / (391 * u.mm * u.pixel)).to(u.arcsecond / u.pixel,
@@ -742,22 +735,6 @@ def test_snr_vs_mag(imager, filter_name, tmpdir):
     assert mags3[-1].value == pytest.approx(mags[-1].value - 2.5, abs=0.1)
 
 
-def test_get_pixel_coords_no_WCS_call_first(imager_function_scope):
-    # test if get_pixel_coords is called without first running set_WCS_centre
-    with pytest.raises(ValueError):
-        imager_function_scope.get_pixel_coords()
-
-
-def test_get_pixel_coords_with_WCS_call_first(imager_function_scope):
-    test_coord_string = "189.9976325 -11.6230544"
-
-    # now set WCS centre first, then try and get_pixel_coords
-    imager_function_scope.set_WCS_centre(test_coord_string, unit='deg')
-    centre_field_pixels = imager_function_scope.get_pixel_coords()
-    assert imager_function_scope.wcs._naxis1 == centre_field_pixels.shape[1]
-    assert imager_function_scope.wcs._naxis2 == centre_field_pixels.shape[0]
-
-
 def test_create_imagers():
     imagers = create_imagers()
     assert isinstance(imagers, dict)