Merge pull request #2047 from paulromano/dep-res-timeunits

Add time_units argument to ResultsList.get_eigenvalue

openmc/deplete/results_list.py

@@ -14,6 +14,17 @@ from openmc.exceptions import DataError, InvalidArgumentError
 __all__ = ["ResultsList"]
 
 
+def _get_time_as(seconds, units):
+    if units == "d":
+        return seconds / (60 * 60 * 24)
+    elif units == "h":
+        return seconds / (60 * 60)
+    elif units == "min":
+        return seconds / 60
+    else:
+        return seconds
+
+
 class ResultsList(list):
     """A list of openmc.deplete.Results objects
 
@@ -99,13 +110,7 @@ class ResultsList(list):
             concentrations[i] = result[0, mat_id, nuc]
 
         # Unit conversions
-        if time_units == "d":
-            times /= (60 * 60 * 24)
-        elif time_units == "h":
-            times /= (60 * 60)
-        elif time_units == "min":
-            times /= 60
-
+        times = _get_time_as(times, time_units)
         if nuc_units != "atoms":
             # Divide by volume to get density
             concentrations /= self[0].volume[mat_id]
@@ -160,19 +165,26 @@ class ResultsList(list):
 
         return times, rates
 
-    def get_eigenvalue(self):
+    def get_eigenvalue(self, time_units='s'):
         """Evaluates the eigenvalue from a results list.
 
+        Parameters
+        ----------
+        time_units : {"s", "d", "h", "min"}, optional
+            Desired units for the times array
+
         Returns
         -------
         times : numpy.ndarray
-            Array of times in [s]
+            Array of times in specified units
         eigenvalues : numpy.ndarray
             k-eigenvalue at each time. Column 0
             contains the eigenvalue, while column
             1 contains the associated uncertainty
 
         """
+        cv.check_value("time_units", time_units, {"s", "d", "min", "h"})
+
         times = np.empty_like(self, dtype=float)
         eigenvalues = np.empty((len(self), 2), dtype=float)
 
@@ -181,6 +193,8 @@ class ResultsList(list):
             times[i] = result.time[0]
             eigenvalues[i] = result.k[0]
 
+        # Convert time units if necessary
+        times = _get_time_as(times, time_units)
         return times, eigenvalues
 
     def get_depletion_time(self):
@@ -230,7 +244,7 @@ class ResultsList(list):
             1-D vector of time points
 
         """
-        cv.check_type("time_units", time_units, str)
+        cv.check_value("time_units", time_units, {"s", "d", "min", "h"})
 
         times = np.fromiter(
             (r.time[0] for r in self),
@@ -238,18 +252,7 @@ class ResultsList(list):
             count=len(self),
         )
 
-        if time_units == "d":
-            times /= (60 * 60 * 24)
-        elif time_units == "h":
-            times /= (60 * 60)
-        elif time_units == "min":
-            times /= 60
-        elif time_units != "s":
-            raise ValueError(
-                'Unable to set "time_units" to {} since it is not '
-                'in ("s", "d", "min", "h")'.format(time_units)
-            )
-        return times
+        return _get_time_as(times, time_units)
 
     def get_step_where(
         self, time, time_units="d", atol=1e-6, rtol=1e-3

tests/unit_tests/test_deplete_resultslist.py

@@ -58,12 +58,14 @@ def test_get_reaction_rate(res):
 def test_get_eigenvalue(res):
     """Tests evaluating eigenvalue."""
     t, k = res.get_eigenvalue()
+    t_min, k = res.get_eigenvalue(time_units='min')
 
     t_ref = [0.0, 1296000.0, 2592000.0, 3888000.0]
     k_ref = [1.21409662, 1.16518654, 1.25357797, 1.22611968]
     u_ref = [0.0278795195, 0.0233141097, 0.0167899218, 0.0246734716]
 
     np.testing.assert_allclose(t, t_ref)
+    np.testing.assert_allclose(t_min * 60, t_ref)
     np.testing.assert_allclose(k[:, 0], k_ref)
     np.testing.assert_allclose(k[:, 1], u_ref)