update

fealpy/fem/__init__.py

@@ -6,6 +6,7 @@
 from .linear_form import LinearForm
 from .semilinear_form import SemilinearForm
 from .block_form import BlockForm
+from .linear_block_form import LinearBlockForm
 
 ### Cell Operator
 from .scalar_diffusion_integrator import ScalarDiffusionIntegrator

fealpy/fem/linear_block_form.py

@@ -0,0 +1,34 @@
+from .form import Form
+from typing import List,overload, Literal, Optional
+from ..typing import TensorLike
+from ..sparse import COOTensor
+
+from ..backend import backend_manager as bm 
+
+
+
+
+class LinearBlockForm(Form):
+    _V = None
+
+    def __init__(self, blocks:List):
+        self.blocks = blocks
+        self.sparse_shape = self._get_sparse_shape() 
+
+    def _get_sparse_shape(self):
+        shape = [i._get_sparse_shape() for i in self.blocks]
+        return (bm.sum(shape), )
+
+    @overload
+    def assembly(self, *, retain_ints: bool=False) -> TensorLike: ...
+    @overload
+    def assembly(self, *, format: Literal['coo'], retain_ints: bool=False) -> COOTensor: ...
+    @overload
+    def assembly(self, *, format: Literal['dense'], retain_ints: bool=False) -> TensorLike: ...
+    def assembly(self, *, format='dense', retain_ints: bool=False): 
+        self._V = [i.assembly(format=format, retain_ints=retain_ints)for i in self.blocks]
+        self._v = bm.concatenate(self._V)
+        return self._V
+
+Form.register(LinearBlockForm)
+

fealpy/mesh/triangle_mesh.py

@@ -69,6 +69,7 @@ def quadrature_formula(self, q: int, etype: Union[int, str]='cell',
 
         if etype == 2:
             from ..quadrature.stroud_quadrature import StroudQuadrature
+            from ..quadrature import TriangleQuadrature
             if q > 9:
                 quad = StroudQuadrature(2, q)
             else: