preconditioner control

Author: ajnonaka

ExampleCodes/LinearSolvers/GMRES/Poisson/AMReX_GMRES_Poisson.H

@@ -8,7 +8,7 @@
 namespace amrex {
 
 /**
- * \brief Solve Poisson's equation using unpreconditioned GMRES
+ * \brief Solve Poisson's equation using amrex GMRES class
  */
 class GMRESPOISSON
 {
@@ -71,7 +71,7 @@ private:
     BoxArray m_ba;
     DistributionMapping m_dm;
     Geometry m_geom;
-    bool m_use_precond = false;
+    bool m_use_precond;
 
     // store the original RHS needed for Jacobi preconditioner
     MultiFab orig_rhs;

ExampleCodes/LinearSolvers/GMRES/Poisson/inputs

@@ -1,2 +1,4 @@
 n_cell = 32
 max_grid_size = 16
+
+use_precond = 0

ExampleCodes/LinearSolvers/GMRES/Poisson/main.cpp

@@ -22,6 +22,9 @@ int main (int argc, char* argv[])
     // size of each box (or grid)
     int max_grid_size;
 
+    // use preconditioner?
+    int use_precond;
+
     // **********************************
     // READ PARAMETER VALUES FROM INPUT DATA
     // **********************************
@@ -38,6 +41,9 @@ int main (int argc, char* argv[])
 
         // The domain is broken into boxes of size max_grid_size
         pp.get("max_grid_size",max_grid_size);
+
+        use_precond = 0;
+        pp.query("use_precond",use_precond);
     }
 
     // **********************************
@@ -111,6 +117,7 @@ int main (int argc, char* argv[])
     // initial guess
     phi.setVal(0.);
 
+    gmres_poisson.usePrecond(use_precond);
     gmres_poisson.setVerbose(2);
     gmres_poisson.solve(phi, rhs, 1.e-12, 0.);