Change matrix format to CSC in depletion (#2764)

openmc/deplete/abc.py

@@ -543,7 +543,7 @@ class Integrator(ABC):
         User-supplied functions are expected to have the following signature:
         ``solver(A, n0, t) -> n1`` where
 
-            * ``A`` is a :class:`scipy.sparse.csr_matrix` making up the
+            * ``A`` is a :class:`scipy.sparse.csc_matrix` making up the
               depletion matrix
             * ``n0`` is a 1-D :class:`numpy.ndarray` of initial compositions
               for a given material in atoms/cm3
@@ -921,7 +921,7 @@ class SIIntegrator(Integrator):
         User-supplied functions are expected to have the following signature:
         ``solver(A, n0, t) -> n1`` where
 
-            * ``A`` is a :class:`scipy.sparse.csr_matrix` making up the
+            * ``A`` is a :class:`scipy.sparse.csc_matrix` making up the
               depletion matrix
             * ``n0`` is a 1-D :class:`numpy.ndarray` of initial compositions
               for a given material in atoms/cm3
@@ -1023,7 +1023,7 @@ def __call__(self, A, n0, dt):
 
         Parameters
         ----------
-        A : scipy.sparse.csr_matrix
+        A : scipy.sparse.csc_matrix
             Sparse transmutation matrix ``A[j, i]`` describing rates at
             which isotope ``i`` transmutes to isotope ``j``
         n0 : numpy.ndarray

openmc/deplete/chain.py

@@ -596,7 +596,7 @@ def form_matrix(self, rates, fission_yields=None):
 
         Returns
         -------
-        scipy.sparse.csr_matrix
+        scipy.sparse.csc_matrix
             Sparse matrix representing depletion.
 
         See Also
@@ -680,11 +680,11 @@ def form_matrix(self, rates, fission_yields=None):
                 # Clear set of reactions
                 reactions.clear()
 
-        # Use DOK matrix as intermediate representation, then convert to CSR and return
+        # Use DOK matrix as intermediate representation, then convert to CSC and return
         n = len(self)
         matrix_dok = sp.dok_matrix((n, n))
         dict.update(matrix_dok, matrix)
-        return matrix_dok.tocsr()
+        return matrix_dok.tocsc()
 
     def form_rr_term(self, tr_rates, mats):
         """Function to form the transfer rate term matrices.
@@ -713,7 +713,7 @@ def form_rr_term(self, tr_rates, mats):
 
         Returns
         -------
-        scipy.sparse.csr_matrix
+        scipy.sparse.csc_matrix
             Sparse matrix representing transfer term.
 
         """
@@ -746,7 +746,7 @@ def form_rr_term(self, tr_rates, mats):
         n = len(self)
         matrix_dok = sp.dok_matrix((n, n))
         dict.update(matrix_dok, matrix)
-        return matrix_dok.tocsr()
+        return matrix_dok.tocsc()
 
     def get_branch_ratios(self, reaction="(n,gamma)"):
         """Return a dictionary with reaction branching ratios

openmc/deplete/cram.py

@@ -75,9 +75,9 @@ def __call__(self, A, n0, dt):
             Final compositions after ``dt``
 
         """
-        A = sp.csr_matrix(A * dt, dtype=np.float64)
+        A = dt * sp.csc_matrix(A, dtype=np.float64)
         y = n0.copy()
-        ident = sp.eye(A.shape[0], format='csr')
+        ident = sp.eye(A.shape[0], format='csc')
         for alpha, theta in zip(self.alpha, self.theta):
             y += 2*np.real(alpha*sla.spsolve(A - theta*ident, y))
         return y * self.alpha0