Nuke obsolete function: directionalDerivative

src/bisection-example-new.cc

@@ -38,17 +38,6 @@ class SampleFunctional {
     return y * v + func_(v.two_norm()); // <1/2 Av - b,v> + H(|v|)
   }
 
-  // Assumes |dir| = 1.
-  double directionalDerivative(const SmallVector x,
-                               const SmallVector dir) const {
-    assert(abs(dir.two_norm() - 1) < 1e-8);
-
-    if (x == SmallVector(0.0))
-      return func_.rightDifferential(0);
-
-    return (x * dir > 0) ? PlusGrad(x) * dir : MinusGrad(x) * dir;
-  }
-
   SmallVector minimise(const SmallVector x) const {
     SmallVector descDir = ModifiedGradient(x);