Adding svo interface to webservice

pyphot/svo.py

@@ -0,0 +1,83 @@
+""" Link to the SVO filter profile service
+
+http://svo2.cab.inta-csic.es/theory/fps/
+
+If your research benefits from the use of the SVO Filter Profile Service, include the following acknowledgement in your publication:
+
+> This research has made use of the SVO Filter Profile Service
+> (http://svo2.cab.inta-csic.es/theory/fps/) supported from the Spanish MINECO
+> through grant AYA2017-84089.
+
+and please include the following references in your publication:
+
+* The SVO Filter Profile Service. Rodrigo, C., Solano, E., Bayo, A., 2012; https://ui.adsabs.harvard.edu/abs/2012ivoa.rept.1015R/abstract
+* The SVO Filter Profile Service. Rodrigo, C., Solano, E., 2020; https://ui.adsabs.harvard.edu/abs/2020sea..confE.182R/abstract
+
+Example
+-------
+
+>>> lst = "2MASS/2MASS.J 2MASS/2MASS.H 2MASS/2MASS.Ks HST/ACS_WFC.F475W HST/ACS_WFC.F814W".split()
+    objects = [get_pyphot_filter(k) for k in lst]
+"""
+from io import BytesIO
+import requests
+from astropy.io import votable
+
+QUERY_URL = "http://svo2.cab.inta-csic.es/theory/fps/fps.php"
+DETECTOR_TYPE = ['energy', 'photon']    # svo returns 0, 1
+
+
+def get_pyphot_astropy_filter(identifier: str):
+    """ Query the SVO filter profile service and return the filter object
+
+    Parameters
+    ----------
+    identifier : str
+        SVO identifier of the filter profile
+        e.g., 2MASS/2MASS.Ks HST/ACS_WFC.F475W
+        The identifier is the first column on the webpage of the facilities.
+
+    Returns
+    -------
+    filter : pyphot.astropy.UnitFilter
+        Filter object
+    """
+    from .astropy import UnitFilter
+    query = {'ID': identifier}
+    response = requests.get(QUERY_URL, params=query)
+    response.raise_for_status()
+    table = votable.parse_single_table(BytesIO(response.content))
+    params = {p.name: p.value for p in table.params}
+    tab = table.to_table()
+    return UnitFilter(tab['Wavelength'].to('nm'),
+                      tab['Transmission'],
+                      name=params['filterID'].replace('/', '_'),
+                      dtype=DETECTOR_TYPE[int(params['DetectorType'])])
+
+
+def get_pyphot_filter(identifier: str):
+    """ Query the SVO filter profile service and return the filter object
+
+    Parameters
+    ----------
+    identifier : str
+        SVO identifier of the filter profile
+        e.g., 2MASS/2MASS.Ks HST/ACS_WFC.F475W
+        The identifier is the first column on the webpage of the facilities.
+
+    Returns
+    -------
+    filter : pyphot.astropy.UnitFilter
+        Filter object
+    """
+    from .sandbox import UnitFilter
+    query = {'ID': identifier}
+    response = requests.get(QUERY_URL, params=query)
+    response.raise_for_status()
+    table = votable.parse_single_table(BytesIO(response.content))
+    params = {p.name: p.value for p in table.params}
+    tab = table.to_table()
+    return UnitFilter(tab['Wavelength'].to('nm'),
+                      tab['Transmission'],
+                      name=params['filterID'].replace('/', '_'),
+                      dtype=DETECTOR_TYPE[int(params['DetectorType'])])