Make functions virtual

src/nicefunction.hh

@@ -14,22 +14,26 @@ class NiceFunction : public VirtualFunction<double, double> {
 
 class SampleFunction : public NiceFunction {
 public:
-  void evaluate(const double& x, double& y) const {
+  void virtual evaluate(const double& x, double& y) const {
     y = (x < 1) ? x : (2 * x - 1);
   }
 
-  double leftDifferential(const double s) const { return (s <= 1) ? 1 : 2; }
+  double virtual leftDifferential(const double s) const {
+    return (s <= 1) ? 1 : 2;
+  }
 
-  double rightDifferential(const double s) const { return (s < 1) ? 1 : 2; }
+  double virtual rightDifferential(const double s) const {
+    return (s < 1) ? 1 : 2;
+  }
 };
 
 class TrivialFunction : public NiceFunction {
 public:
-  void evaluate(const double& x, double& y) const { y = 0; }
+  void virtual evaluate(const double& x, double& y) const { y = 0; }
 
-  double leftDifferential(const double) const { return 0; }
+  double virtual leftDifferential(const double) const { return 0; }
 
-  double rightDifferential(const double) const { return 0; }
+  double virtual rightDifferential(const double) const { return 0; }
 };
 }
 #endif