fix dot

src/OPALtypes.h

@@ -65,13 +65,21 @@ inline double euclidean_norm(const Vector_t<T, D>& v) {
     return std::sqrt(dot(v, v).apply());
 }
 
-// dot product
+// dot products
 template <class T, unsigned D>
 inline double dot(const Vector_t<T, D>& v, const Vector_t<T, D>& w) {
-    T res = 0.0;
+    double res = 0.0;
     for (unsigned i = 0; i < D; i++)
         res += v(i) * w(i);
-    return std::sqrt(res);
+    return res;
+}
+
+template <class T, unsigned D>
+inline double dot(const Vector_t<T, D>& v) {
+    double res = 0.0;
+    for (unsigned i = 0; i < D; i++)
+        res += v(i) * v(i);
+    return res;
 }
 
 #endif
\ No newline at end of file

src/Steppers/BorisPusher.h

@@ -131,8 +131,7 @@ inline void BorisPusher::push(
      * R[i] += 0.5 * P[i] * recpgamma;
      * \endcode
      */
-    const double dp = P(0) * P(0) + P(1) * P(1) + P(2) * P(2);  // \todo dot(P,P) does not work
-    R += 0.5 * P / std::sqrt(1.0 + dp);
+    R += 0.5 * P / std::sqrt(1.0 + dot(P));
 }
 
 #endif