Add proper error if the central wavelengths aren't specified

avocado/astronomical_object.py

@@ -7,7 +7,7 @@
 import pandas as pd
 from scipy.optimize import minimize
 
-from .instruments import band_central_wavelengths, get_band_plot_color
+from .instruments import get_band_central_wavelength, get_band_plot_color
 from .utils import logger
 
 class AstronomicalObject():
@@ -68,7 +68,7 @@ def bands(self):
         """
         unsorted_bands = np.unique(self.observations['band'])
         sorted_bands = np.array(sorted(unsorted_bands,
-                                       key=band_central_wavelengths.get))
+                                       key=get_band_central_wavelength))
         return sorted_bands
 
     def subtract_background(self):
@@ -171,7 +171,7 @@ def fit_gaussian_process(self, fix_scale=False, verbose=False,
         fluxes = gp_observations['flux']
         flux_errors = gp_observations['flux_error']
 
-        wavelengths = gp_observations['band'].map(band_central_wavelengths)
+        wavelengths = gp_observations['band'].map(get_band_central_wavelength)
         times = gp_observations['time']
 
         # Use the highest signal-to-noise observation to estimate the scale. We
@@ -301,7 +301,7 @@ def predict_gaussian_process(self, bands, times, uncertainties=True,
 
         for band in bands:
             wavelengths = (
-                np.ones(len(times)) * band_central_wavelengths[band]
+                np.ones(len(times)) * get_band_central_wavelength(band)
             )
             pred_x_data = np.vstack([times, wavelengths]).T
             if uncertainties:

avocado/augment.py

@@ -6,7 +6,7 @@
 
 from .astronomical_object import AstronomicalObject
 from .dataset import Dataset
-from .instruments import band_central_wavelengths
+from .instruments import get_band_central_wavelength
 from .utils import settings, logger
 
 class Augmentor():
@@ -330,7 +330,7 @@ def _resample_light_curve(self, reference_object, augmented_metadata):
             reference_redshift = reference_object.metadata['host_specz']
             redshift_scale = (1 + new_redshift) / (1 + reference_redshift)
 
-            new_wavelengths = np.array([band_central_wavelengths[i] for i in
+            new_wavelengths = np.array([get_band_central_wavelength(i) for i in
                                         observations['band']])
             eval_wavelengths = new_wavelengths / redshift_scale
             pred_x_data = np.vstack([observations['reference_time'],

avocado/instruments.py

@@ -3,7 +3,9 @@
 This module is used to define properties of various instruments. This should
 eventually be split out into some kind of configuration file setup.
 """
+from .utils import AvocadoException
 
+# Central wavelengths for each band.
 band_central_wavelengths = {
     'lsstu': 3671.,
     'lsstg': 4827.,
@@ -23,6 +25,25 @@
     'lssty': 'goldenrod',
 }
 
+def get_band_central_wavelength(band):
+    """Return the central wavelength for a given band.
+
+    If the band does not yet have a color assigned to it, an AvocadoException
+    is raised.
+
+    Parameters
+    ----------
+    band : str
+        The name of the band to use.
+    """
+    if band in band_central_wavelengths:
+        return band_central_wavelengths[band]
+    else:
+        raise AvocadoException(
+            "Central wavelength unknown for band %s. Add it to "
+            "avocado.instruments.band_central_wavelengths." % band
+        )
+
 def get_band_plot_color(band):
     """Return the plot color for a given band.