poly deg conditions

Fixed a bug where the default degrees for unsaved polynomial fits were
not matching those of the saved psf coefficients. Added a `quick`
keyword for that feature instead of tying it to the `save` keyword.

pynrc/nrc_utils.py

@@ -964,7 +964,7 @@ def psf_coeff(filter_or_bp, pupil=None, mask=None, module='A',
     fov_pix=11, oversample=None, npsf=None, ndeg=None, tel_pupil=None,
     offset_r=None, offset_theta=None, jitter=None, jitter_sigma=0.007, 
     opd=None, wfe_drift=None, drift_file=None, include_si_wfe=True, 
-    detector=None, detector_position=None, force=False, 
+    detector=None, detector_position=None, force=False, quick=False,
     save=True, save_name=None, return_save_name=False, **kwargs):
     """Generate PSF coefficients
     
@@ -1003,7 +1003,8 @@ def psf_coeff(filter_or_bp, pupil=None, mask=None, module='A',
         produce 20 PSFs/um. The wavelength range is determined by
         choosing those wavelengths where throughput is >0.001.
     ndeg : int
-        Polynomial degree for PSF fitting. Default = 10.
+        Polynomial degree for PSF fitting. 
+        Default = 10 (7 if quick=True).
     offset_r : float
         Radial offset from the center in arcsec.
     offset_theta :float
@@ -1038,10 +1039,16 @@ def psf_coeff(filter_or_bp, pupil=None, mask=None, module='A',
     save_name : str, None
         Full path name of FITS file to save/load coefficents. 
         If None, then a name is automatically generated.
+    quick : bool
+        Only perform a fit over the filter bandpass with a smaller default
+        polynomial degree fit. Not compatible with save.
     return_save_name : bool
 
 
     """
+
+    if (save and quick):
+        raise ValueError("Keywords `save` and `quick` cannot both be set to True.")
 
     grism_obs = (pupil is not None) and ('GRISM' in pupil)
     dhs_obs   = (pupil is not None) and ('DHS'   in pupil)
@@ -1231,14 +1238,14 @@ def psf_coeff(filter_or_bp, pupil=None, mask=None, module='A',
         inst.pupilopd = opd
 
     # By default, WebbPSF has wavelength limits depending on the channel
-    # We don't care about this, so set these to low/high values
+    # which can interfere with pynrc calculations, so set these to low/high values
     inst.SHORT_WAVELENGTH_MIN = inst.LONG_WAVELENGTH_MIN = 1e-7
     inst.SHORT_WAVELENGTH_MAX = inst.LONG_WAVELENGTH_MAX = 10e-6
 
     # Select which wavelengths to use
-    # When saving the data, we want the full channel wavelength
-    # However, if doing a "quick" PSF, only fit the filter wavelength range
-    if save:
+    # If doing a "quick" PSF, only fit the filter wavelength range.
+    # Otherwise, we fit the full channel wavelength.
+    if quick:
         w1,w2 = (0.5,2.5) if 'SW' in chan_str else (2.4,5.1)
     else:
         w1 = bp.wave.min() / 1e4
@@ -1311,7 +1318,7 @@ def psf_coeff(filter_or_bp, pupil=None, mask=None, module='A',
     # Simultaneous polynomial fits to all pixels using linear least squares
     # 7th-degree polynomial seems to do the trick
     if ndeg is None:
-        ndeg = 10 if save else 7
+        ndeg = 10 if quick else 7
     coeff_all = jl_poly_fit(waves, images, ndeg)
 
     if save:

pynrc/obs_nircam.py

@@ -112,7 +112,7 @@ def __init__(self, sp_sci, sp_ref, distance, wfe_ref_drift=10, offset_list=None,
         if verbose: print("Generating oversampled PSFs...")
         _, psf = self.gen_psf(return_oversample=True, use_bg_psf=False)
         self.psf_center_over = psf
-        if self.mask is not None:
+        if self.mask is None:
             self.psf_offaxis_over = self.psf_center_over
         else:
             _, psf = self.gen_psf(return_oversample=True, use_bg_psf=True)
@@ -725,7 +725,7 @@ class (``self.nrc_ref.update_detectors()``).
         -------
         tuple
             Three arrays in a tuple: the radius in arcsec, n-sigma contrast,
-            and n-sigma magnitude limit (vega mag). 
+            and n-sigma magnitude sensitivity limit (vega mag). 
         """
         from astropy.convolution import convolve, Gaussian1DKernel
 
@@ -779,7 +779,7 @@ class (``self.nrc_ref.update_detectors()``).
             im_mask = pad_or_cut_to_size(im_mask, data.shape)
 
             nx = im_mask.shape[0]
-            xv = (np.arange(nx) - nx/2) * pixscale_over
+            xv = (np.arange(nx) - nx/2) * pixscale
 
             # a and b coefficients at each offset location
             avals = np.interp(rr, xv, im_mask[nx//2,:]**2)
@@ -1014,11 +1014,11 @@ def saturation_levels(self, full_size=True, ngroup=0, **kwargs):
             If False, use fov_pix size.
         ngroup : int
             How many group times to determine saturation level?
+            If this number is higher than the total groups in ramp, 
+            then a warning is produced.
             The default is ngroup=0, which corresponds to the
-            so-called "zero-frame." This is the very first frame
-            that is read-out and saved separately. If this number
-            is higher than the total groups in ramp, then a
-            warning is produced.
+            so-called "zero-frame," which is the very first frame
+            that is read-out and saved separately. 
         
         """
 

pynrc/pynrc_core.py

@@ -945,6 +945,9 @@ class NIRCam(object):
         Save the resulting PSF coefficients to a file? (default: True)
     force : bool
         Forces a recalcuation of PSF even if saved PSF exists. (default: False)
+    quick : bool
+        Only perform a fit over the filter bandpass with a smaller default
+        polynomial degree fit. Not compatible with save.
         
     Examples
     --------
@@ -1472,7 +1475,7 @@ def update_psf_coeff(self, fov_pix=None, oversample=None,
             Tuple (file, slice) or filename or HDUList specifying OPD.
         wfe_drift : float
             Wavefront error drift amplitude in nm.
-            Updates :attr:`wfe_drift` attribute.
+            Updates :attr:`wfe_drift` attribute and coefficients appropriately.
         tel_pupil : str
             File name or HDUList specifying telescope entrance pupil.
         jitter : str or None
@@ -1552,7 +1555,7 @@ def update_psf_coeff(self, fov_pix=None, oversample=None,
 
         # WFE Drift is handled differently than the rest of the parameters
         # This is because we use wfed_coeff() to determine the resid values
-        # for the PSF coefficients to generated a drifted PSF.
+        # for the PSF coefficients to generate a drifted PSF.
         if wfe_drift is not None:
             self._wfe_drift = wfe_drift