How to assemble the right hand side when the source is on a different mesh?
Hi everyone !
Domain B is a sub domain of domain \Omega. B_h and \Omega_h are different triangulations which means B_h is not the sub mesh of \Omega.
Now, I want to assemble \int_{B_h}f\cdot v as the right hand side where f is a vector function and v is a test function in \Omega_h. I have calculated the Gauss points and weights for every cell in B_h. Therefore, \int_{B_h}f\cdot v=\Sigma w_i f_i v_i can be set as an item of PETSCVector. ( i mean function evaluates at $i$th Gauss point)
I can find the cell contains a given gauss point. However, how to evaluate basis function on the cell and find its index in PETSCVector ?