def create_mass_matrix(field):
"""
Create scalar mass matrix corresponding to the given field.
Returns
-------
mtx : csr_matrix
The mass matrix in CSR format.
"""
u = FieldVariable('u', 'unknown', field)
v = FieldVariable('v', 'test', field, primary_var_name='u')
integral = Integral('i', order=field.approx_order * 2)
term = Term.new('dw_volume_dot(v, u)', integral, field.region, v=v, u=u)
eq = Equation('aux', term)
eqs = Equations([eq])
eqs.time_update(None)
dummy = eqs.create_state_vector()
mtx = eqs.create_matrix_graph()
mtx = eqs.eval_tangent_matrices(dummy, mtx)
return mtx
def create_mass_matrix(field):
"""
Create scalar mass matrix corresponding to the given field.
Returns
-------
mtx : csr_matrix
The mass matrix in CSR format.
"""
u = FieldVariable('u', 'unknown', field)
v = FieldVariable('v', 'test', field, primary_var_name='u')
integral = Integral('i', order=field.approx_order * 2)
term = Term.new('dw_volume_dot(v, u)', integral, field.region, v=v, u=u)
eq = Equation('aux', term)
eqs = Equations([eq])
eqs.time_update(None)
dummy = eqs.create_state_vector()
mtx = eqs.create_matrix_graph()
mtx = eqs.eval_tangent_matrices(dummy, mtx)
return mtx
