From 9368ff05753ddbf5c00f6c12e2f4bcd9ce034867 Mon Sep 17 00:00:00 2001
From: Anton Khirnov <anton@khirnov.net>
Date: Thu, 25 Jul 2019 10:57:54 +0200
Subject: Set the initial guess on refined levels.

---
 src/qms.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/src/qms.c b/src/qms.c
index 162bd47..d931eef 100644
--- a/src/qms.c
+++ b/src/qms.c
@@ -914,6 +914,16 @@ void qms_mg_solve(CCTK_ARGUMENTS)
                 }
             }
         }
+
+        {
+            /* use the solution from the coarser level as the initial guess */
+            CoordPatch *cp_coarse = get_coord_patch(ms, reflevel - 1);
+
+            ret = mg2d_init_guess(cp->solver, cp_coarse->solver->u, cp_coarse->solver->u_stride,
+                                  cp_coarse->solver->local_start, cp_coarse->solver->local_size, cp_coarse->solver->step);
+            if (ret < 0)
+                CCTK_WARN(0, "Error setting the initial guess");
+        }
     }
 
     fprintf(stderr, "%d qms solve: time %g\n", reflevel, time);
-- 
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