Wrap PCBDDC

firedrake/preconditioners/__init__.py

@@ -12,3 +12,4 @@
 from firedrake.preconditioners.fdm import *          # noqa: F401
 from firedrake.preconditioners.hiptmair import *     # noqa: F401
 from firedrake.preconditioners.facet_split import *  # noqa: F401
+from firedrake.preconditioners.bddc import *         # noqa: F401

firedrake/preconditioners/bddc.py

@@ -0,0 +1,49 @@
+from firedrake.preconditioners.base import PCBase
+from firedrake.preconditioners.patch import bcdofs
+from firedrake.petsc import PETSc
+from firedrake.dmhooks import get_appctx
+import numpy
+
+
+__all__ = ("BDDCPC",)
+
+
+class BDDCPC(PCBase):
+    """PC for PETSc PCBDDC"""
+
+    _prefix = "bddc"
+
+    def initialize(self, pc):
+        # Get context from pc
+        _, P = pc.getOperators()
+        dm = pc.getDM()
+        self.prefix = pc.getOptionsPrefix() + self._prefix
+
+        # Create new PC object as BDDC type
+        bddcpc = PETSc.PC().create(comm=pc.comm)
+        bddcpc.incrementTabLevel(1, parent=pc)
+        bddcpc.setOptionsPrefix(self.prefix)
+        bddcpc.setOperators(*pc.getOperators())
+        bddcpc.setType(PETSc.PC.Type.BDDC)
+
+        ctx = get_appctx(dm)
+        bcs = tuple(ctx._problem.bcs)
+        if len(bcs) > 0:
+            bc_nodes = numpy.unique(numpy.concatenate([bcdofs(bc, ghost=False) for bc in bcs]))
+            bndr = PETSc.IS().createGeneral(bc_nodes, comm=pc.comm)
+            bddcpc.setBDDCDirichletBoundariesLocal(bndr)
+
+        bddcpc.setFromOptions()
+        self.pc = bddcpc
+
+    def view(self, pc, viewer=None):
+        self.pc.view(viewer=viewer)
+
+    def update(self, pc):
+        pass
+
+    def apply(self, pc, x, y):
+        self.pc.apply(x, y)
+
+    def applyTranspose(self, pc, x, y):
+        self.pc.applyTranspose(x, y)