From e2881681724433b249cb9a97225e02f35dc862e9 Mon Sep 17 00:00:00 2001
From: Elias Pipping <elias.pipping@fu-berlin.de>
Date: Wed, 21 Mar 2012 14:13:03 +0100
Subject: [PATCH] Make RuinaFunction convex(!)
---
dune/tectonic/nicefunction.hh | 49 ++++++++++++++++-------------------
1 file changed, 23 insertions(+), 26 deletions(-)
diff --git a/dune/tectonic/nicefunction.hh b/dune/tectonic/nicefunction.hh
index b34ca7e0..6a30e338 100644
--- a/dune/tectonic/nicefunction.hh
+++ b/dune/tectonic/nicefunction.hh
@@ -27,7 +27,9 @@ class NiceFunction {
// Whether H(|.|) is smooth at zero
bool virtual smoothesNorm() const { return false; }
- void virtual evaluate(double const &x, double &y) const = 0;
+ void virtual evaluate(double const &x, double &y) const {
+ DUNE_THROW(NotImplemented, "evaluation not implemented");
+ }
};
class RuinaFunction : public NiceFunction {
@@ -35,30 +37,20 @@ class RuinaFunction : public NiceFunction {
RuinaFunction(double coefficient, double a, double mu, double eta,
double normalStress, double b, double state, double L, double h)
: a(a),
+ mu(mu),
+ eta(eta),
h(h),
coefficientProduct(coefficient * normalStress),
- c(mu + (a - b) * std::log(eta) - b * std::log(L)),
- K(b * state) // state is assumed to be logarithmic
- {}
-
- void virtual evaluate(double const &x, double &y) const {
- double const arg = x / h;
- if (arg == 0) { // TODO: Make this controllable
- y = 0;
- return;
- }
-
- double const expstar = arg * std::log(arg) - arg;
- y = a * expstar + (c + K) * arg;
- y *= coefficientProduct * h;
- }
+ K(b *
+ (state - std::log(eta * L))), // state is assumed to be logarithmic
+ rho(std::exp(-(mu + K) / a)) {}
double virtual leftDifferential(double x) const {
- double const arg = x / h;
- if (arg < 1e-14) // TODO: Make this controllable
+ double const arg = x / h * eta;
+ if (arg <= rho)
return 0;
- double const ret = (a * std::log(arg) + c + K);
+ double const ret = a * std::log(arg) + mu + K;
return coefficientProduct * ret;
}
@@ -66,26 +58,31 @@ class RuinaFunction : public NiceFunction {
return leftDifferential(s);
}
- double virtual second_deriv(double s) const {
- if (s < 1e-14) // TODO: Make this controllable
+ double virtual second_deriv(double x) const {
+ double const arg = x / h * eta;
+ if (arg <= rho)
return 0;
- return coefficientProduct * a / s;
+ return coefficientProduct * a / x;
}
- double virtual regularity(double s) const {
- if (s == 0)
+ double virtual regularity(double x) const {
+ double const arg = x / h * eta;
+ // TODO: Make this controllable
+ if (arg < 1e-14 || std::abs(arg - rho) < 1e-14)
return std::numeric_limits<double>::infinity();
- return std::abs(second_deriv(s));
+ return std::abs(second_deriv(x));
}
private:
double const a;
+ double const mu;
+ double const eta;
double const h;
double const coefficientProduct;
- double const c;
double const K;
+ double const rho;
};
class LinearFunction : public NiceFunction {
--
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