This program has been adapted from the var_coeff program written by Dhairya Malhotra.


COMPILING
---------
Require: PETSc, PvFMM
PETSC_DIR and PVFMM_DIR must be defined.
PvFMM can be downloaded from: https://github.com/dmalhotra/pvfmm

To compile:
> make

Troubleshooting:
Modify Makefile as needed.


COMMANDLINE OPTIONS
-------------------
-eta        <Real>   Inf norm of \eta*0.1
-ref_tol    <Real>   Tree refinement tolerance
-min_depth  <Int>    Minimum tree depth
-max_depth  <Int>    Maximum tree depth
-fmm_q      <Int>    Chebyshev polynomial degree
-fmm_m      <Int>    Multipole order (+ve even integer)
-gmres_tol  <Real>   GMRES residual tolerance
-gmres_iter <Int>    GMRES maximum iterations

Example: ./bin/invmed -eta 1 -ref_tol 1e-4 min_depth 3 -max_depth 5 -gmres_tol 1e-6