include a magnification limit to remove highly de-magnified images

CONTRIBUTING.rst

@@ -29,6 +29,17 @@ Finally add the ``sim-pipeline-project`` repository as a *remote*. This will all
   git remote add sim-pipeline-project https://github.com/LSST-strong-lensing/sim-pipeline.git
 
 
+Install sim-pipeline in development mode
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+To run your own version of sim-pipeline and making sure that your own development changes are reflected (as well as switcing branches),
+install the sim-pipeline package in development mode with
+
+::
+
+  cd sim-pipeline
+  python setup.py develop --user
+
+
 Create a branch for your new feature
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 

sim_pipeline/galaxy_galaxy_lens.py

@@ -21,6 +21,7 @@ def __init__(
         mixgauss_means=None,
         mixgauss_stds=None,
         mixgauss_weights=None,
+        magnification_limit=0.01
     ):
         """
 
@@ -39,6 +40,9 @@ def __init__(
         :type mixgauss_weights: list of float
         :type mixgauss_stds: list of float
         :type mixgauss_means: list of float
+        :param magnification_limit: absolute lensing magnification lower limit to
+            register a point source (ignore highly de-magnified images)
+        :type magnification_limit: float >= 0
         """
         self._source_dict = source_dict
         self._lens_dict = deflector_dict
@@ -48,6 +52,7 @@ def __init__(
         self._mixgauss_means = mixgauss_means
         self._mixgauss_stds = mixgauss_stds
         self._mixgauss_weights = mixgauss_weights
+        self._magnification_limit = magnification_limit
         if self._lens_dict["z"] >= self._source_dict["z"]:
             self._theta_E_sis = 0
         else:
@@ -97,8 +102,8 @@ def source_position(self):
 
     def image_positions(self):
         """Return image positions by solving the lens equation. These are either the
-        centers of the extended source, or the point sources in case of (added) point-
-        like sources, such as quasars or SNe.
+        centers of the extended source, or the point sources in case of (added)
+        point-like sources, such as quasars or SNe.
 
         :return: x-pos, y-pos
         """
@@ -119,6 +124,7 @@ def image_positions(self):
                 solver="lenstronomy",
                 search_window=self.einstein_radius * 6,
                 min_distance=self.einstein_radius * 6 / 100,
+                magnification_limit=self._magnification_limit
             )
         return self._image_positions
 
@@ -172,7 +178,9 @@ def validity_test(
         # Criteria 6: (optional)
         # compute the magnified brightness of the lensed extended arc for different
         # bands at least in one band, the magnitude has to be brighter than the limit
-        if mag_arc_limit is not None:
+        if mag_arc_limit is not None and self._source_type in ['extended']:
+            # makes sure magnification of extended source is only used when there is
+            # an extended source
             bool_mag_limit = False
             host_mag = self.host_magnification()
             for band, mag_limit_band in mag_arc_limit.items():