Making n sub intervals a config class parameter

src/sorcha/ephemeris/simulation_driver.py

@@ -80,6 +80,8 @@ def create_ephemeris(orbits_df, pointings_df, args, sconfigs):
         nside : integer
             The nside value used for the HEALPIx calculations.  Must be a
             power of 2 (1, 2, 4, ...)  nside=64 is current default.
+        n_sub_intervals: int
+            Number of sub-intervals for the Lagrange interpolation (default: 101)
 
     Returns
     -------
@@ -109,7 +111,7 @@ def create_ephemeris(orbits_df, pointings_df, args, sconfigs):
     picket_interval = sconfigs.simulation.ar_picket
     obsCode = sconfigs.simulation.ar_obs_code
     nside = 2**sconfigs.simulation.ar_healpix_order
-    n_sub_intervals = 101  # configs["n_sub_intervals"]
+    n_sub_intervals = sconfigs.simulation.n_sub_intervals
 
     ephemeris_csv_filename = None
     if args.output_ephemeris_file and args.outpath:

src/sorcha/utilities/sorchaConfigs.py

@@ -77,6 +77,9 @@ class simulationConfigs:
     ar_healpix_order: int = None
     """the order of healpix which we will use for the healpy portions of the code."""
 
+    n_sub_intervals: int = None
+    """Number of sub-intervals for the Lagrange ephemerides interpolation (default: 101)"""
+
     _ephemerides_type: str = None
     """Simulation used for ephemeris input."""
 
@@ -111,6 +114,7 @@ def _validate_simulation_configs(self):
             self.ar_fov_buffer = cast_as_float(self.ar_fov_buffer, "ar_fov_buffer")
             self.ar_picket = cast_as_int(self.ar_picket, "ar_picket")
             self.ar_healpix_order = cast_as_int(self.ar_healpix_order, "ar_healpix_order")
+            self.n_sub_intervals = cast_as_int_or_set_default(self.n_sub_intervals, "n_sub_intervals", 101)
         elif self._ephemerides_type == "external":
             # makes sure when these are not needed that they are not populated
             check_key_doesnt_exist(self.ar_ang_fov, "ar_ang_fov", "but ephemerides type is external")
@@ -1307,6 +1311,39 @@ def cast_as_bool_or_set_default(value, key, default):
         return default
 
 
+def cast_as_int_or_set_default(value, key, default):
+
+    # replaces PPGetBoolOrExit: checks to make sure the value can be cast as a bool.
+    """
+    Checks to see if value can be cast as an int and if not set (equals None) gives default int.
+
+    Parameters
+    -----------
+    value : object attribute
+        value of the config file attribute
+
+    key : string
+        The key being checked.
+
+    default : int
+        default int if value is None
+
+    Returns
+    ----------
+    value as an int
+    """
+
+    if value is not None:
+        try:
+            int(value)
+        except ValueError:
+            logging.error(f"ERROR: expected an int for config parameter {key}. Check value in config file.")
+            sys.exit(f"ERROR: expected an int for config parameter {key}. Check value in config file.")
+        return value
+    elif value is None:
+        return default
+
+
 def PrintConfigsToLog(sconfigs, cmd_args):
     """
     Prints all the values from the config file and command line to the log.

tests/sorcha/test_sorchaConfigs.py

@@ -35,6 +35,7 @@
     "ar_picket": 1,
     "ar_obs_code": "X05",
     "ar_healpix_order": 6,
+    "n_sub_intervals": 101
 }
 
 correct_filters_read = {"observing_filters": "r,g,i,z,u,y", "survey_name": "rubin_sim"}
@@ -261,7 +262,7 @@ def test_simulationConfigs_float(key_name):
     )
 
 
-@pytest.mark.parametrize("key_name", ["ar_picket", "ar_healpix_order"])
+@pytest.mark.parametrize("key_name", ["ar_picket", "ar_healpix_order","n_sub_intervals"])
 def test_simulationConfigs_int(key_name):
     """
     Tests that wrong inputs for simulationConfigs int attributes is caught correctly