message: adjust amgx defaults based on lessons learned
diff: @@ -208,11 +208,14 @@ void AmgXSolver::DefaultParameters(const AMGX_MODE amgxMode_,
  " \"config_version\": 2, \n"
  " \"solver\": { \n"
  " \"solver\": \"AMG\", \n"
  + " \"scope\": \"main\", \n"
  + " \"smoother\": \"JACOBI_L1\", \n"
  " \"presweeps\": 1, \n"
  - " \"postsweeps\": 1, \n"
  " \"interpolator\": \"D2\", \n"
  - " \"max_iters\": 2, \n"
  - " \"convergence\": \"ABSOLUTE\", \n"
  + " \"max_row_sum\" : 0.9, \n"
  + " \"strength_threshold\" : 0.25, \n"
  + " \"postsweeps\": 1, \n"
  + " \"max_iters\": 1, \n"
  " \"cycle\": \"V\"";
  if (verbose)
  {
  @@ -239,22 +242,21 @@ void AmgXSolver::DefaultParameters(const AMGX_MODE amgxMode_,
  " \"solver\": \"AMG\", \n"
  " \"smoother\": { \n"
  " \"scope\": \"jacobi\", \n"
  - " \"solver\": \"BLOCK_JACOBI\", \n"
  - " \"relaxation_factor\": 0.7 \n"
  + " \"solver\": \"JACOBI_L1\", \n"
  " }, \n"
  " \"presweeps\": 1, \n"
  " \"interpolator\": \"D2\", \n"
  " \"max_row_sum\" : 0.9, \n"
  " \"strength_threshold\" : 0.25, \n"
  - " \"max_iters\": 2, \n"
  + " \"max_iters\": 1, \n"
  " \"scope\": \"amg\", \n"
  " \"max_levels\": 100, \n"
  " \"cycle\": \"V\", \n"
  " \"postsweeps\": 1 \n"
  " }, \n"
  " \"solver\": \"PCG\", \n"
  - " \"max_iters\": 100, \n"
  - " \"convergence\": \"RELATIVE_MAX\", \n"
  + " \"max_iters\": 150, \n"
  + " \"convergence\": \"RELATIVE_INI_CORE\", \n"
  " \"scope\": \"main\", \n"
  " \"tolerance\": 1e-12, \n"
  " \"monitor_residual\": 1, \n"
  