[Noise] Do not store logrest

dune/tectonic/frictionpotential.hh

@@ -33,11 +33,10 @@ class FrictionPotential : public FrictionPotentialWrapper {
       : fd(_fd), weight(coefficient), normalStress(_normalStress) {}
 
   double coefficientOfFriction(double V) const {
-    assert(V >= 0.0);
     if (V <= Vmin)
       return 0.0;
 
-    return fd.a * (std::log(V / fd.V0) + logrest);
+    return fd.a * std::log(V / Vmin);
   }
 
   double differential(double V) const {
@@ -45,7 +44,6 @@ class FrictionPotential : public FrictionPotentialWrapper {
   }
 
   double second_deriv(double V) const {
-    assert(V >= 0);
     if (V <= Vmin)
       return 0;
 
@@ -53,7 +51,6 @@ class FrictionPotential : public FrictionPotentialWrapper {
   }
 
   double regularity(double V) const {
-    assert(V >= 0);
     if (std::abs(V - Vmin) < 1e-14) // TODO
       return std::numeric_limits<double>::infinity();
 
@@ -61,7 +58,7 @@ class FrictionPotential : public FrictionPotentialWrapper {
   }
 
   void updateAlpha(double alpha) {
-    logrest = (fd.mu0 + fd.b * alpha) / fd.a;
+    double const logrest = (fd.mu0 + fd.b * alpha) / fd.a;
     Vmin = fd.V0 / std::exp(logrest);
   }
 
@@ -69,7 +66,6 @@ class FrictionPotential : public FrictionPotentialWrapper {
   FrictionData const fd;
   double const weight;
   double const normalStress;
-  double logrest;
   double Vmin;
 };