new API for lookups

docs/index.rst

@@ -21,6 +21,53 @@ Contents
 Simple example
 ^^^^^^^^^^^^^^
 
+Find available filters like this:
+
+.. code-block:: python
+
+    >>> from tynt.lookup import filters
+    >>> # filters.<TAB>  # this works in a Jupyter environment, OR:
+    >>> dir(filters)  # this works in any interactive environment
+    ['CAHA',
+     'CHEOPS',
+     'CTIO',
+     'GAIA',
+     ...
+
+To see the filters available within a filter set:
+
+.. code-block:: python
+
+    >>> from tynt.lookup import filters
+
+    >>> filters.Kepler
+    <FilterSet: "Kepler"
+      Available filters: ["Kepler_K"]>
+
+Plot the filter transmittance curve:
+
+.. plot::
+    :include-source:
+
+    from tynt.lookup import filters
+
+    filters.Kepler.Kepler_K.plot()
+
+Compare several optical filters:
+
+.. plot::
+    :include-source:
+
+    from tynt.lookup import filters
+
+    filters.Kepler.Kepler_K.plot(label='Kepler')
+    filters.CHEOPS.CHEOPS_band.plot(label='CHEOPS')
+    filters.TESS.TESS_Red.plot(label='TESS')
+
+
+FilterGenerator
+^^^^^^^^^^^^^^^
+
 Let's plot the transmittance curve of the SDSS r' filter:
 
 .. plot::

setup.cfg

@@ -17,6 +17,8 @@ setup_requires = setuptools_scm
 install_requires = 
    numpy
    astropy
+   matplotlib
+   scipy
 
 [options.extras_require]
 all =

tynt/core.py

@@ -1,12 +1,15 @@
 import os
 
 import numpy as np
+import matplotlib.pyplot as plt
+
 import astropy.units as u
 from astropy.io import fits
-from astropy.table import Table
-from astropy.utils.data import download_file
 from astropy.modeling import models
 from astropy.modeling.tabular import Tabular1D
+from astropy.table import Table
+from astropy.utils.data import download_file
+from astropy.visualization import quantity_support
 
 __all__ = ['FilterGenerator', 'Filter']
 
@@ -17,7 +20,7 @@ class FilterGenerator:
     """
     Astronomical filter object generator.
     """
-    def __init__(self, path=None):
+    def __init__(self, path=None, name=None):
         """
         Parameters
         ----------
@@ -28,6 +31,7 @@ def __init__(self, path=None):
             path = data_path
 
         self.path = path
+        self.name = name
         self.table = Table(fits.getdata(path))
         self.table.add_index('Filter name')
 
@@ -152,8 +156,11 @@ def fft_model(x):
 
             astropy_model = fft_model()
 
+        filter_set, filter_name = identifier.split('/')
         return Filter(
-            wavelength * u.Angstrom, transmittance, model=astropy_model
+            wavelength * u.Angstrom, transmittance,
+            filter_set=filter_set, filter_name=identifier,
+            model=astropy_model
         )
 
     def download_true_transmittance(self, identifier, **kwargs):
@@ -174,18 +181,28 @@ def download_true_transmittance(self, identifier, **kwargs):
                              f'theory/fps3/fps.php?ID={identifier}', **kwargs)
 
         true_transmittance = Table.read(path, format='votable')
+
+        filter_set, filter_name = identifier.split('/')
+
         return Filter(
             true_transmittance['Wavelength'].data.data * u.Angstrom,
-            true_transmittance['Transmission'].data.data
+            true_transmittance['Transmission'].data.data,
+            filter_set=filter_set, filter_name=identifier
         )
 
 
+_filter_generator = FilterGenerator()
+
+
 class Filter:
     """
     Astronomical filter.
     """
     @u.quantity_input(wavelength=u.m)
-    def __init__(self, wavelength, transmittance, model=None):
+    def __init__(
+            self, wavelength=None, transmittance=None,
+            model=None, filter_set=None, filter_name=None
+    ):
         """
         Parameters
         ----------
@@ -196,9 +213,39 @@ def __init__(self, wavelength, transmittance, model=None):
         model : ~astropy.modeling.Model
             Astropy model for the transmittance curve
         """
-        self.wavelength = wavelength
-        self.transmittance = transmittance
+        self._wavelength = wavelength
+        self._transmittance = transmittance
         self.model = model
+        self.filter_set = filter_set
+        self.filter_name = filter_name
+
+    @property
+    def wavelength(self):
+        if self._wavelength is None:
+            self._get_filter_from_name()
+        return self._wavelength
+
+    @wavelength.setter
+    def wavelength(self, value):
+        if value is not None:
+            self._wavelength = value
+
+    @property
+    def transmittance(self):
+        if self._transmittance is None:
+            self._get_filter_from_name()
+        return self._transmittance
+
+    @transmittance.setter
+    def transmittance(self, value):
+        if value is not None:
+            self._transmittance = value
+
+    def _get_filter_from_name(self):
+        name = f"{self.filter_set}/{self.filter_name.replace('__', '.')}"
+        filt = _filter_generator.reconstruct(name)
+        self.wavelength = filt.wavelength
+        self.transmittance = filt.transmittance
 
     @property
     def table(self):
@@ -212,3 +259,25 @@ def table(self):
         """
         return Tabular1D(points=self.wavelength,
                          lookup_table=self.transmittance)
+
+    def __repr__(self):
+        if None not in (self.filter_name, self.filter_set):
+            return f"<Filter: {self.filter_set}/{self.filter_name}>"
+        return "<Filter>"
+
+    def plot(self, ax=None, x_unit=u.um, y_label='Transmittance', **kwargs):
+
+        if ax is None:
+            ax = plt.gca()
+
+        label = kwargs.pop('label', self.filter_name)
+
+        with quantity_support():
+            ax.plot(
+                self.wavelength.to(x_unit), self.transmittance,
+                label=label, **kwargs
+            )
+            ax.legend()
+
+        if y_label is not None:
+            ax.set(ylabel=y_label)

tynt/lookup.py

@@ -0,0 +1,73 @@
+from collections import defaultdict
+from tynt.core import Filter, _filter_generator
+
+__all__ = ['filters']
+
+
+class FilterSet:
+
+    def __init__(self, filter_set, filter_names):
+        self._filter_set = filter_set
+        self._filter_names = filter_names
+        self.filters = set()
+        for filter_name in filter_names:
+            fname = filter_name.replace('.', '_')
+            setattr(
+                self, fname,
+                Filter(filter_set=filter_set, filter_name=filter_name)
+            )
+            self.filters.add(f'"{fname}"')
+
+    def __repr__(self):
+        return (f"<FilterSet: \"{self._filter_set}\"\n  "
+                f"Available filters: [{', '.join(sorted(self.filters))}]>")
+
+
+def assemble_filter_sets():
+
+    filter_sets = defaultdict(list)
+
+    for name in _filter_generator.available_filters():
+        filter_set, filter_name = name.split('/')
+        filter_sets[filter_set].append(filter_name)
+
+    sets = dict()
+    for filter_set, filter_names in filter_sets.items():
+        sets[filter_set] = FilterSet(filter_set, filter_names)
+
+    return sets
+
+
+class DefaultFacilities:
+    TWOMASS = None
+    SLOAN = None
+    Kepler = None
+    TESS = None
+    HST = None
+    JWST = None
+    LSST = None
+    Keck = None
+    WISE = None
+    WFIRST = None
+    Roman = None
+    Spitzer = None
+    GAIA = None
+    CHEOPS = None
+
+
+class FilterLookup(DefaultFacilities):
+    _accessors = set()
+
+    def __init__(self):
+
+        filter_sets = assemble_filter_sets()
+
+        for name, filter_set in filter_sets.items():
+            if name[0].isnumeric():
+                name = name.replace('2', 'TWO')
+
+            setattr(self, name, filter_set)
+            self._accessors.add(name)
+
+
+filters = FilterLookup()

tynt/tests/test_core.py

@@ -1,9 +1,11 @@
 import pytest
 import numpy as np
-from astropy.tests.helper import assert_quantity_allclose
+
 import astropy.units as u
+from astropy.tests.helper import assert_quantity_allclose
+from scipy.integrate import trapezoid
 
-from ..core import FilterGenerator
+from tynt.core import FilterGenerator
 
 filter_generator = FilterGenerator()
 
@@ -68,11 +70,11 @@ def test_lambda_eff_w_eff(
     for identifier in filters:
         filt = filter_generator.reconstruct(identifier)
 
-        lambda_bar_approx = (np.trapz(filt.transmittance * filt.wavelength,
-                                      filt.wavelength) /
-                             np.trapz(filt.transmittance, filt.wavelength))
+        lambda_bar_approx = (trapezoid(filt.transmittance * filt.wavelength,
+                                       filt.wavelength) /
+                             trapezoid(filt.transmittance, filt.wavelength))
 
-        width_approx = (np.trapz(filt.transmittance, filt.wavelength) /
+        width_approx = (trapezoid(filt.transmittance, filt.wavelength) /
                         filt.transmittance.max())
 
         w_eff_approx.append(width_approx)