]> https://gitweb.dealii.org/ - dealii.git/commitdiff
Fix a bug reported by Vaibhav Palkar on the mailing where the time step for embedded...
authorBruno Turcksin <bruno.turcksin@gmail.com>
Fri, 16 Sep 2016 14:26:00 +0000 (10:26 -0400)
committerBruno Turcksin <bruno.turcksin@gmail.com>
Fri, 16 Sep 2016 14:26:00 +0000 (10:26 -0400)
doc/news/changes.h
examples/step-52/doc/results.dox
include/deal.II/base/time_stepping.templates.h

index 79bb0c43536a952c9e0f383cb34e880c039d2317..215b0dfb6de39bb05da27600289fd5929c2e894e 100644 (file)
@@ -529,6 +529,11 @@ inconvenience this causes.
 <h3>Specific improvements</h3>
 
 <ol>
+ <li> Fixed: EmbeddedRungeKutta methods now correctly increase delta_t_guess 
+ when the error is below coarsen_tol.
+ </br>
+ (Vaibhav Palkar, Bruno Turcksin, 2016/09/16)
+ </li>
 
  <li> New: LinearAlgebra::Vector is now instantiated for float and double.
  <br>
index 4c2d9ea0b0d90ce9e98889f434a5d69841035e5c..8311f7fda07a43d28cd0f299f53a6a5b231c2dde 100644 (file)
@@ -23,18 +23,18 @@ SDIRK:                    error=0.0042349
 Embedded %explicit methods:
 Heun-Euler:               error=0.0073012
                 steps performed=284
-Bogacki-Shampine:         error=0.000207511
-                steps performed=200
-Dopri:                    error=4.01774e-09
-                steps performed=200
-Fehlberg:                 error=9.89504e-09
-                steps performed=200
-Cash-Karp:                error=2.55791e-10
-                steps performed=200
+Bogacki-Shampine:         error=0.000403281
+                steps performed=181
+Dopri:                    error=0.0165485
+                steps performed=119
+Fehlberg:                 error=0.00104926
+                steps performed=106
+Cash-Karp:                error=8.59366e-07
+                steps performed=107
+
 @endcode
 
 As expected the higher order methods give (much) more accurate solutions. We
-also see that the (rather inaccurate) Heun-Euler method adapted the number of
+also see that the (rather inaccurate) Heun-Euler method increased the number of
 time steps in order to satisfy the tolerance. On the other hand, the other
-embedded methods did not need to change the number of time steps as they are
-easily able to reach the desired tolerance with the given time step size.
+embedded methods used a lot less time steps than what was prescribed.
index d36af60f435283a4a7ae2fb6ff6560d975c45799..509c1b332454d54531afae2d41a78e41e273b7bc 100644 (file)
@@ -727,7 +727,7 @@ namespace TimeStepping
             else
               {
                 status.exit_delta_t = DELTA_T;
-                status.delta_t_guess = delta_t;
+                status.delta_t_guess = new_delta_t;
               }
           }
         // Check if the norm of error is less than the refining tolerance

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