From aae2defb03a9de8556129618e9e641f58bef0a55 Mon Sep 17 00:00:00 2001
From: Elias Pipping <elias.pipping@fu-berlin.de>
Date: Mon, 16 Dec 2013 13:10:44 +0100
Subject: [PATCH] [Algorit] Make minimisation terminate
---
dune/tectonic/minimisation.hh | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
diff --git a/dune/tectonic/minimisation.hh b/dune/tectonic/minimisation.hh
index 5bf0888b..0e27a654 100644
--- a/dune/tectonic/minimisation.hh
+++ b/dune/tectonic/minimisation.hh
@@ -28,6 +28,14 @@ template <class Functional>
void minimise(Functional const &J, typename Functional::LocalVector &x,
size_t steps, Bisection const &bisection) {
using LocalVector = typename Functional::LocalVector;
+ auto const diff = [](LocalVector const &a, LocalVector const &b) {
+ LocalVector tmp = a;
+ tmp -= b;
+ return tmp.two_norm();
+ };
+
+ LocalVector x_initial = x;
+ LocalVector x_o = x;
for (size_t step = 0; step < steps; ++step) {
LocalVector v;
@@ -40,6 +48,20 @@ void minimise(Functional const &J, typename Functional::LocalVector &x,
double const alpha = lineSearch(J, x, v, bisection);
Arithmetic::addProduct(x, alpha, v);
+
+ if (alpha < 1e-14) // TODO
+ break;
+
+ double const correction = diff(x, x_o);
+ double const overallCorrection = diff(x, x_initial);
+ if (overallCorrection <= 0.0)
+ return;
+
+ double const correctionQuotient = correction / overallCorrection;
+ if (correctionQuotient < 0.1) // enough descent; TODO
+ break;
+
+ x_o = x;
}
}
#endif
--
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