Fix definition of RuinaFunction

dune/tectonic/nicefunction.hh

@@ -35,14 +35,14 @@ 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),
-        eta_h(eta / h),
+        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 = eta_h * x;
+    double const arg = x / h;
     if (arg == 0) { // TODO: Make this controllable
       y = 0;
       return;
@@ -50,11 +50,11 @@ class RuinaFunction : public NiceFunction {
 
     double const expstar = arg * std::log(arg) - arg;
     y = a * expstar + (c + K) * arg;
-    y *= coefficientProduct / eta_h;
+    y *= coefficientProduct * h;
   }
 
   double virtual leftDifferential(double x) const {
-    double const arg = eta_h * x;
+    double const arg = x / h;
     if (arg < 1e-14) // TODO: Make this controllable
       return 0;
 
@@ -82,7 +82,7 @@ class RuinaFunction : public NiceFunction {
 
 private:
   double const a;
-  double const eta_h;
+  double const h;
   double const coefficientProduct;
   double const c;
   double const K;