Change how incoherent elastic data is written to HDF5

openmc/data/angle_energy.py

@@ -43,8 +43,8 @@ class AngleEnergy(EqualityMixin, metaclass=ABCMeta):
             return openmc.data.IncoherentElasticAEDiscrete.from_hdf5(group)
         elif dist_type == 'incoherent_inelastic_discrete':
             return openmc.data.IncoherentInelasticAEDiscrete.from_hdf5(group)
-        elif dist_type == 'incoherent_inelastic_continuous':
-            return openmc.data.IncoherentInelasticAEContinuous.from_hdf5(group)
+        elif dist_type == 'incoherent_inelastic':
+            return openmc.data.IncoherentInelasticAE.from_hdf5(group)
 
     @staticmethod
     def from_ace(ace, location_dist, location_start, rx=None):

openmc/data/function.py

@@ -591,8 +591,8 @@ class Regions1D(EqualityMixin):
         Functions which are to be combined in a piecewise fashion
     breakpoints : Iterable of float
         The values of the dependent variable that define the domain of
-        each function. The `i`th and `(i+1)`th values are the limits of the
-        domain of the `i`th function. Values must be monotonically increasing.
+        each function. The `i`\ th and `(i+1)`\ th values are the limits of the
+        domain of the `i`\ th function. Values must be monotonically increasing.
 
     Attributes
     ----------

openmc/data/thermal.py

@@ -24,7 +24,7 @@ from .njoy import make_ace_thermal
 from .thermal_angle_energy import (CoherentElasticAE, IncoherentElasticAE,
                                    IncoherentElasticAEDiscrete,
                                    IncoherentInelasticAEDiscrete,
-                                   IncoherentInelasticAEContinuous)
+                                   IncoherentInelasticAE)
 
 
 _THERMAL_NAMES = {
@@ -247,26 +247,26 @@ class IncoherentElastic(Function1D):
 
     Parameters
     ----------
-    xs : float
+    bound_xs : float
         Characteristic bound cross section in [b]
     debye_waller : float
         Debye-Waller integral in [eV\ :math:`^{-1}`]
 
     Attributes
     ----------
-    xs : float
+    bound_xs : float
         Characteristic bound cross section in [b]
     debye_waller : float
         Debye-Waller integral in [eV\ :math:`^{-1}`]
 
     """
-    def __init__(self, xs, debye_waller):
-        self.xs = xs
+    def __init__(self, bound_xs, debye_waller):
+        self.bound_xs = bound_xs
         self.debye_waller = debye_waller
 
     def __call__(self, E):
         W = self.debye_waller
-        return self.xs / 2.0 * (1 - np.exp(-4*E*W)) / (2*E*W)
+        return self.bound_xs / 2.0 * (1 - np.exp(-4*E*W)) / (2*E*W)
 
     def to_hdf5(self, group, name):
         """Write incoherent elastic scattering to an HDF5 group
@@ -279,14 +279,27 @@ class IncoherentElastic(Function1D):
             Name of the dataset to create
 
         """
-        dataset = group.create_dataset(name)
+        data = np.array([self.bound_xs, self.debye_waller])
+        dataset = group.create_dataset(name, data=data)
         dataset.attrs['type'] = np.string_(type(self).__name__)
-        dataset.attrs['debye_waller'] = self.debye_waller
-        dataset.attrs['bound_xs'] = self.xs
 
     @classmethod
     def from_hdf5(cls, dataset):
-        return cls(dataset.attrs['xs'], dataset.attrs['debye_waller'])
+        """Read incoherent elastic scattering from an HDF5 dataset
+
+        Parameters
+        ----------
+        dataset : h5py.Dataset
+            HDF5 dataset to read from
+
+        Returns
+        -------
+        openmc.data.IncoherentElastic
+            Incoherent elastic scattering cross section
+
+        """
+        bound_xs, debye_waller = dataset[()]
+        return cls(bound_xs, debye_waller)
 
 
 class ThermalScatteringReaction(EqualityMixin):
@@ -676,7 +689,7 @@ class ThermalScattering(EqualityMixin):
             breakpoints = [n_energy]
             interpolation = [2]
             energy = inelastic_xs.x
-            distribution = IncoherentInelasticAEContinuous(
+            distribution = IncoherentInelasticAE(
                 breakpoints, interpolation, energy, energy_out, mu_out)
 
         table = cls(name, ace.atomic_weight_ratio, energy_max, kTs)

openmc/data/thermal_angle_energy.py

@@ -106,7 +106,7 @@ class IncoherentInelasticAEDiscrete(AngleEnergy):
     mu_out : numpy.ndarray
         Discrete angles for each incoming/outgoing energy
     skewed : bool
-        Whether distance angles are equi-probable or have a skewed distribution
+        Whether discrete angles are equi-probable or have a skewed distribution
 
     Attributes
     ----------
@@ -115,7 +115,7 @@ class IncoherentInelasticAEDiscrete(AngleEnergy):
     mu_out : numpy.ndarray
         Discrete angles for each incoming/outgoing energy
     skewed : bool
-        Whether distance angles are equi-probable or have a skewed distribution
+        Whether discrete angles are equi-probable or have a skewed distribution
 
     """
     def __init__(self, energy_out, mu_out, skewed=False):
@@ -137,5 +137,5 @@ class IncoherentInelasticAEDiscrete(AngleEnergy):
         return cls(energy_out, mu_out, skewed)
 
 
-class IncoherentInelasticAEContinuous(CorrelatedAngleEnergy):
+class IncoherentInelasticAE(CorrelatedAngleEnergy):
     _name = 'incoherent_inelastic'

src/endf.cpp

@@ -1,6 +1,7 @@
 #include "openmc/endf.h"
 
 #include <algorithm> // for copy
+#include <array>
 #include <cmath>     // for log, exp
 #include <iterator>  // for back_inserter
 #include <stdexcept> // for runtime_error
@@ -244,8 +245,10 @@ double CoherentElasticXS::operator()(double E) const
 
 IncoherentElasticXS::IncoherentElasticXS(hid_t dset)
 {
-  read_attribute(dset, "bound_xs", bound_xs_);
-  read_attribute(dset, "debye_waller", debye_waller_);
+  std::array<double, 2> tmp;
+  read_dataset(dset, nullptr, tmp);
+  bound_xs_ = tmp[0];
+  debye_waller_ = tmp[1];
 }
 
 double IncoherentElasticXS::operator()(double E) const