How to find out the reason for my error?

Errors
1

Hi. I am new to FENICS. I am currently trying to solve a PDE that is similar to that of Neo-Hookean material model but is different in certain parameters. I have tried following the methods that have been taught in the manuals. I am so far able to replicate some of the problems.

However, for this unique numerical problem for myself I get the following error message:

TypeError: solve(): incompatible function arguments. The following argument types are supported:
1. (A: dolfin.cpp.la.GenericLinearOperator, x: dolfin.cpp.la.GenericVector, b: dolfin.cpp.la.GenericVector, method: str = ‘lu’, preconditioner: str = ‘none’) → int

Invoked with: False, Coefficient(FunctionSpace(Mesh(VectorElement(FiniteElement(‘Lagrange’, triangle, 1), dim=2), 50), VectorElement(FiniteElement(‘Lagrange’, triangle, 1), dim=2)), 58), [<dolfin.fem.dirichletbc.DirichletBC object at 0x7f3f05e86b90>, <dolfin.fem.dirichletbc.DirichletBC object at 0x7f3f05e86c50>], ‘default’, ‘default’

a=inner(Xi,nabla_grad(v))

L=dot(T,v)

Fi=a-L

solve(Fi==0, u, bcs)

this is the solve formatting I am using. Here Xi is a second order tensor and v is the test function. Here tensor T is also a first order tensor.

Because I am new in FENICS I do not know exactly what is the reason for the problem. I want to correct my code by myself, however, I do not know what might be the cause of the error. If you could let me know what is this error message referring to it would be very helpful.

2

You are missing integration measures (dx or ds) in your variational form.
For further questions, please make sure that you:

  1. post a minimal code that reproduces the error
  2. use markdown formatting, i.e.
```python
from dolfin import *
def f(x):
    return x
```