From b64994a389effc4a1ef34aafcadef86d1319321c Mon Sep 17 00:00:00 2001
From: Walter Van Herck <w.van.herck@fz-juelich.de>
Date: Tue, 7 May 2013 16:50:05 +0200
Subject: [PATCH] Improved numerics for SpecularMatrix calculation
---
Core/Algorithms/inc/SpecularMatrix.h | 3 +-
Core/Algorithms/src/SpecularMatrix.cpp | 47 ++++++++++----------------
dev-tools/log/perf_history.txt | 1 +
3 files changed, 20 insertions(+), 31 deletions(-)
diff --git a/Core/Algorithms/inc/SpecularMatrix.h b/Core/Algorithms/inc/SpecularMatrix.h
index b0b988bbb02..bebd2e4bf85 100644
--- a/Core/Algorithms/inc/SpecularMatrix.h
+++ b/Core/Algorithms/inc/SpecularMatrix.h
@@ -68,8 +68,7 @@ private:
bool m_use_roughness;
void calculateEigenvalues(const MultiLayer& sample, const kvector_t& k, MultiLayerCoeff_t& coeff) const;
- void calculateTransferMatrices(const MultiLayer& sample, const kvector_t& k, MultiLayerCoeff_t& coeff) const;
- void calculateBoundaryValues(MultiLayerCoeff_t& coeff) const;
+ void calculateTransferAndBoundary(const MultiLayer& sample, const kvector_t& k, MultiLayerCoeff_t& coeff) const;
};
#endif /* SPECULARMATRIX_H_ */
diff --git a/Core/Algorithms/src/SpecularMatrix.cpp b/Core/Algorithms/src/SpecularMatrix.cpp
index 07b0c097f6b..f6cc9e96395 100644
--- a/Core/Algorithms/src/SpecularMatrix.cpp
+++ b/Core/Algorithms/src/SpecularMatrix.cpp
@@ -24,9 +24,7 @@ void SpecularMatrix::execute(const MultiLayer& sample, const kvector_t& k,
calculateEigenvalues(sample, k, coeff);
- calculateTransferMatrices(sample, k, coeff);
-
- calculateBoundaryValues(coeff);
+ calculateTransferAndBoundary(sample, k, coeff);
}
void SpecularMatrix::calculateEigenvalues(const MultiLayer& sample,
@@ -42,13 +40,15 @@ void SpecularMatrix::calculateEigenvalues(const MultiLayer& sample,
}
}
-void SpecularMatrix::calculateTransferMatrices(const MultiLayer& sample,
+void SpecularMatrix::calculateTransferAndBoundary(const MultiLayer& sample,
const kvector_t& k, MultiLayerCoeff_t& coeff) const
{
- // Layer 0 gets identity matrix:
- coeff[0].l.setIdentity();
- coeff.L.setIdentity();
- for(size_t i=1; i<coeff.size()-1; ++i) {
+ size_t N = coeff.size();
+ // Last layer boundary ensures no reflection
+ coeff[N-1].phi_psi(0) = -coeff[N-1].lambda;
+ coeff[N-1].phi_psi(1) = 1.0;
+ coeff[N-1].l.setIdentity();
+ for(size_t i=N-2; i>0; --i) {
complex_t lambda = coeff[i].lambda;
complex_t kdlambda = k.mag()*sample.getLayer(i)->getThickness()*lambda;
complex_t cosine_term = std::cos(kdlambda);
@@ -57,28 +57,17 @@ void SpecularMatrix::calculateTransferMatrices(const MultiLayer& sample,
k.mag()*sample.getLayer(i)->getThickness() :
std::sin(kdlambda)/lambda;
coeff[i].l(0,0) = cosine_term;
- coeff[i].l(0,1) = -complex_t(0.0, 1.0)*lambda*lambda*sine_term;
- coeff[i].l(1,0) = -complex_t(0.0, 1.0)*sine_term;
+ coeff[i].l(0,1) = complex_t(0.0, 1.0)*lambda*lambda*sine_term;
+ coeff[i].l(1,0) = complex_t(0.0, 1.0)*sine_term;
coeff[i].l(1,1) = cosine_term;
- coeff.L = coeff[i].l * coeff.L;
+ coeff[i].phi_psi = coeff[i].l * coeff[i+1].phi_psi;
}
- // Last layer also gets identity matrix:
- size_t N = coeff.size();
- coeff[N-1].l.setIdentity();
-}
-
-void SpecularMatrix::calculateBoundaryValues(MultiLayerCoeff_t& coeff) const
-{
- complex_t lambda0 = coeff[0].lambda;
- size_t N = coeff.size();
- complex_t lambdaN = coeff[N-1].lambda;
- complex_t denominator = (lambda0*coeff.L(0,0) + coeff.L(0,1) + lambdaN*(lambda0*coeff.L(1,0) + coeff.L(1,1)));
- coeff.R = (lambda0*coeff.L(0,0) - coeff.L(0,1) + lambdaN*(lambda0*coeff.L(1,0) - coeff.L(1,1)))/denominator;
- // Boundary values at bottom of top layer
- // and top of first layer:
- coeff[1].phi_psi(0) = coeff[0].phi_psi(0) = lambda0*(coeff.R - 1.0);
- coeff[1].phi_psi(1) = coeff[0].phi_psi(1) = coeff.R + 1.0;
- for(size_t i=2; i<coeff.size(); ++i) {
- coeff[i].phi_psi = coeff[i-1].l*coeff[i-1].phi_psi;
+ // First layer boundary is also top layer boundary:
+ coeff[0].l.setIdentity();
+ coeff[0].phi_psi = coeff[1].phi_psi;
+ // Normalize all boundary values with top layer transmitted wave:
+ complex_t T0 = coeff[0].T();
+ for (size_t i=0; i<N; ++i) {
+ coeff[i].phi_psi = coeff[i].phi_psi/T0;
}
}
diff --git a/dev-tools/log/perf_history.txt b/dev-tools/log/perf_history.txt
index cf9e623a2a2..0dd59d8ac0b 100644
--- a/dev-tools/log/perf_history.txt
+++ b/dev-tools/log/perf_history.txt
@@ -246,3 +246,4 @@
# added performance method for matrix calculation of layer wave amplitudes
2013-05-07 16:05:21 | jcnsopc74 | macosx64, 2800 MHz | 294118 | 11.976 | 11.976 | 3.63636 | 1.05263e+06 |
+2013-05-07 16:44:53 | jcnsopc74 | macosx64, 2800 MHz | 298507 | 11.9048 | 11.8343 | 3.63636 | 1.05263e+06 |
--
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