ENH add DES gal cat

environment.yaml

@@ -8,6 +8,7 @@ dependencies:
   - astropy
   - pandas
   - des-eastlake
+  - des-y6utils
   - galsim_extra
   - importlib_metadata
   - cfitsio  # for fpack

montara/__init__.py

@@ -20,3 +20,4 @@
 from . import badpixfromfits  # noqa
 from . import eastlake_step  # noqa
 from . import eval_gsobject  # noqa
+from . import input_desgal  # noqa

montara/input_desgal.py

@@ -0,0 +1,55 @@
+import galsim
+import numpy as np
+from galsim.config.input import InputLoader, RegisterInputType, GetInputObj
+from galsim.config.value import RegisterValueType
+import fitsio
+from .utils import add_field
+
+
+class DESGalCatalog(object):
+    _req_params = {'file_name': str}
+    _single_params = []
+    _takes_rng = False
+
+    def __init__(self, file_name, mag_i_col='mag_i', mag_i_max=None, mag_i_min=None,
+                 _nobjects_only=False):
+        self.gal_data = fitsio.read(file_name)
+        self.gal_data = add_field(
+            self.gal_data, [("catalog_row", int)],
+            [np.arange(len(self.gal_data))],
+        )
+        self.nobjects = len(self.gal_data)
+
+    def get(self, index, col):
+        return self.gal_data[index][col]
+
+    def getNObjects(self):
+        return self.nobjects
+
+
+def _GenerateFromDESGalCatalog(config, base, value_type):
+    """@brief Return a value read from an input catalog
+    """
+    gal_input = GetInputObj('desgal', config, base, 'DESGalValue')
+
+    # Setup the indexing sequence if it hasn't been specified.
+    # The normal thing with a Catalog is to just use each object in order,
+    # so we don't require the user to specify that by hand.  We can do it for them.
+    galsim.config.SetDefaultIndex(config, gal_input.getNObjects())
+
+    req = {'col': str, 'index': int}
+    opt = {'num': int}
+    kwargs, safe = galsim.config.GetAllParams(config, base, req=req, opt=opt)
+    col = kwargs['col']
+    index = kwargs['index']
+    val = gal_input.get(index, col)
+    return val, safe
+
+
+RegisterInputType('desgal', InputLoader(DESGalCatalog, has_nobj=True))
+RegisterValueType(
+    'DESGalValue',
+    _GenerateFromDESGalCatalog,
+    [float],
+    input_type='desgal',
+)