From cb61d9d8a762c47833aaab41a4bc2954f0c4f3e0 Mon Sep 17 00:00:00 2001
From: Oliver Sander <sander@igpm.rwth-aachen.de>
Date: Thu, 3 Jan 2013 09:38:05 +0000
Subject: [PATCH] Move derivative of F wrt to first argument into separate
method
[[Imported from SVN: r9094]]
---
dune/gfe/hyperbolichalfspacepoint.hh | 29 ++++++++++++++++------------
1 file changed, 17 insertions(+), 12 deletions(-)
diff --git a/dune/gfe/hyperbolichalfspacepoint.hh b/dune/gfe/hyperbolichalfspacepoint.hh
index 393f776a..c3919be7 100644
--- a/dune/gfe/hyperbolichalfspacepoint.hh
+++ b/dune/gfe/hyperbolichalfspacepoint.hh
@@ -48,6 +48,21 @@ class HyperbolicHalfspacePoint
}
}
+ /** \brief Compute derivative of $F(p,q) = 1 + ||p-q||^2 / 2p_nq_n with respect to p
+ \param[in] diffNormSquared Expected to be ||p-q||^2, taken from the caller for efficiency reasons
+ */
+ static Dune::FieldVector<T,N> computeDFdp(const HyperbolicHalfspacePoint& p, const HyperbolicHalfspacePoint& q, const T& diffNormSquared)
+ {
+ Dune::FieldVector<T,N> result;
+
+ for (size_t i=0; i<N-1; i++)
+ result[i] = ( q.data_[i] - p.data_[i] ) / (q.data_[N-1] * p.data_[N-1]);
+
+ result[N-1] = - diffNormSquared / (2*p.data_[N-1]*p.data_[N-1]*q.data_[N-1]) + (p.data_[N-1] - q.data_[N-1]) / (p.data_[N-1]*q.data_[N-1]);
+
+ return result;
+ }
+
/** \brief Compute derivative of $F(p,q) = 1 + ||p-q||^2 / 2p_nq_n with respect to q
\param[in] diffNormSquared Expected to be ||p-q||^2, taken from the caller for efficiency reasons
*/
@@ -240,12 +255,7 @@ public:
T diffNormSquared = (p-q).two_norm2();
// Compute first derivatives of F with respect to p and q
- Dune::FieldVector<T,N> dFdp;
- for (size_t i=0; i<N-1; i++)
- dFdp[i] = ( p[i] - q[i] ) / (p[N-1] * q[N-1]);
-
- dFdp[N-1] = - diffNormSquared / (2*p[N-1]*q[N-1]*q[N-1]) - (p[N-1] - q[N-1]) / (p[N-1]*q[N-1]);
-
+ Dune::FieldVector<T,N> dFdp = computeDFdp(a,b,diffNormSquared);
Dune::FieldVector<T,N> dFdq = computeDFdq(a,b,diffNormSquared);
// Compute second derivatives of F
@@ -420,12 +430,7 @@ public:
T diffNormSquared = (p-q).two_norm2();
// Compute first derivatives of F with respect to p and q
- Dune::FieldVector<T,N> dFdp;
- for (size_t i=0; i<N-1; i++)
- dFdp[i] = ( p[i] - q[i] ) / (p[N-1] * q[N-1]);
-
- dFdp[N-1] = - diffNormSquared / (2*p[N-1]*q[N-1]*q[N-1]) - (p[N-1] - q[N-1]) / (p[N-1]*q[N-1]);
-
+ Dune::FieldVector<T,N> dFdp = computeDFdp(a,b,diffNormSquared);
Dune::FieldVector<T,N> dFdq = computeDFdq(a,b,diffNormSquared);
// Compute second derivatives of F
--
GitLab