From 093c3102e6bb4e3b35d13d9be3f19c4eda876d9e Mon Sep 17 00:00:00 2001
From: Elias Pipping <elias.pipping@fu-berlin.de>
Date: Thu, 9 Jan 2014 14:51:11 +0100
Subject: [PATCH] [Cleanup] Refactor minimisation
---
dune/tectonic/minimisation.hh | 26 +++++++++++---------------
1 file changed, 11 insertions(+), 15 deletions(-)
diff --git a/dune/tectonic/minimisation.hh b/dune/tectonic/minimisation.hh
index 389a0a14..71edb09b 100644
--- a/dune/tectonic/minimisation.hh
+++ b/dune/tectonic/minimisation.hh
@@ -12,22 +12,16 @@
#include "mydirectionalconvexfunction.hh"
template <class Functional>
-void descentMinimisation(Functional const &J,
- typename Functional::LocalVector &x,
- typename Functional::LocalVector const &v,
- Bisection const &bisection) {
- using LocalVector = typename Functional::LocalVector;
- using LocalNonlinearity = typename Functional::Nonlinearity;
-
- MyDirectionalConvexFunction<LocalNonlinearity> const JRest(
+double lineSearch(Functional const &J,
+ typename Functional::LocalVector const &x,
+ typename Functional::LocalVector const &v,
+ Bisection const &bisection) {
+ MyDirectionalConvexFunction<typename Functional::Nonlinearity> const JRest(
computeDirectionalA(J.A, v), computeDirectionalb(J.A, J.b, x, v), *J.phi,
x, v);
- // }}}
int count;
- double const stepsize = bisection.minimize(JRest, 0.0, 0.0, count);
-
- Arithmetic::addProduct(x, stepsize, v);
+ return bisection.minimize(JRest, 0.0, 0.0, count);
}
template <class Functional>
@@ -38,12 +32,14 @@ void minimise(Functional const &J, typename Functional::LocalVector &x,
for (size_t step = 0; step < steps; ++step) {
LocalVector v;
J.gradient(x, v);
- if (v.two_norm() == 0.0)
- return;
+ double const vnorm = v.two_norm();
+ if (vnorm <= 0.0)
+ return;
v *= -1;
- descentMinimisation(J, x, v, bisection);
+ double const alpha = lineSearch(J, x, v, bisection);
+ Arithmetic::addProduct(x, alpha, v);
}
}
#endif
--
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