refactor blockvector bindings to allow for generic types

dune/python/istl/bvector.hh

@@ -111,8 +111,6 @@ namespace Dune
       typedef typename BlockVector::block_type block_type;
       typedef typename BlockVector::size_type size_type;
 
-      registerFieldVecMat<block_type>::apply();
-
       using pybind11::operator""_a;
 
       cls.def( "assign", [] ( BlockVector &self, const BlockVector &x ) { self = x; }, "x"_a );

dune/python/test/bcrsmatrix.py

@@ -99,17 +99,28 @@ for i in range(5):
 y1, y2 = blockVector(5), blockVector(5)
 mat.mv(x, y1)
 mat.asLinearOperator().apply(x, y2)
+
 if (y1 - y2).two_norm > 1e-12:
     raise Exception("mat.mv != mat.asLinearOperator().apply")
 
 S = CGSolver(mat.asLinearOperator(), SeqJacobi(mat), 1e-10)
-mat = None
 z = blockVector(5)
+
 _, _, converged, _, _ = S(z, y1)
 if not converged:
     raise Exception("CGSolver has not converged")
 if (z - x).two_norm > 1e-8:
     raise Exception("CGSolver unable to solve identity")
+vec = dune.common.FieldVector([1])
+z2 = BlockVector(vec,5)
+
+S2=CGSolver(mat.asLinearOperator(),SeqJacobi(mat),1e-10)
+
+_, _, converged2, _, _ = S2(z2, y2)
+if not converged2:
+    raise Exception("CGSolver has not converged")
+if (z2 - x).two_norm > 1e-8:
+    raise Exception("CGSolver unable to solve identity")
 
 s = "(" + ", ".join(str(v) for v in x) + ")"
 

python/dune/istl/__init__.py

@@ -55,19 +55,54 @@ def bcrsMatrix(size=0, *args, **kwargs):
         return BCRSMatrix(blockType)(size,*args)
     return BCRSMatrix(blockType)()
 
+def BlockVector(typeOrBlockSize,size=None):
+    """
+    Create a BlockVector object with specified type or block size for a FieldVector.
 
-def BlockVector(blockSize):
-    if blockSize == 1:
-        return BlockVector1
-    typeName = "Dune::BlockVector< Dune::FieldVector< double ," + str(blockSize) + " > >"
-    includes = ["dune/python/istl/bvector.hh"]
-    # todo: provide other constructors
-    return loadvec(includes, typeName).BlockVector
+    Args:
+        typeOrBlockSize (int or str or object): The type of the block vector or the block size.
+            - If int, specifies the block size directly.
+            - If typeOrBlockSize is not an int, it should have a 'cppTypeName' attribute specifying the type and 'cppIncludes' attribute specifying additional include files.
+        size (int, optional): The size of the vector. Default is None.
+
+    Returns:
+        BlockVector: The created BlockVector object.
+    """
+    typeName=[]
+    includes=["dune/python/istl/bvector.hh"]
+    if hasattr (typeOrBlockSize, "cppTypeName") and hasattr (typeOrBlockSize, "cppIncludes"):
+
+        typeName = f"Dune::BlockVector< {typeOrBlockSize.cppTypeName} >"
+
+        includes += typeOrBlockSize.cppIncludes
+        if size is None:
+           return loadvec(includes,typeName).BlockVector
+        bvec = loadvec(includes,typeName).BlockVector(size)
+        for i in range(len(bvec)):
+            bvec[i]=typeOrBlockSize
+        return bvec
+    else:
+        if typeOrBlockSize == 1:
+            if size is None:
+                return BlockVector1
+            else:
+                return BlockVector1(size)
+        dune.common.FieldVector(typeOrBlockSize) # make sure that the FieldVector is registered    
+        typeName = "Dune::BlockVector<Dune::FieldVector< double, " + str(typeOrBlockSize) + " > >"
+    if size is None:
+        return loadvec(includes, typeName).BlockVector
+    else:
+        return loadvec(includes, typeName).BlockVector(size)
 
 def blockVector(size, blockSize=1):
-    if blockSize == 1:
-        return BlockVector1(size)
-    typeName = "Dune::BlockVector< Dune::FieldVector< double ," + str(blockSize) + " > >"
-    includes = ["dune/istl/bvector.hh"]
-    # todo: provide other constructors
-    return loadvec(includes, typeName).BlockVector(size)
+    """
+    Creates a Dune BlockVector object of size `size` with FieldVector<double,`blockSize`> as blocks.
+
+    Args:
+        size (int): The size of the vector.
+        blockSize (int, optional): The block size. Default is 1.
+
+    Returns:
+        BlockVector: The created BlockVector object.
+    """
+    return BlockVector(blockSize,size)