         f+= sqEkvec[z]*normalamp[z]*cos(kvec[z]*RZphasecos+normalphase[z]); 
       }      
     }
-    return amp_*norm*f;
+    return amp_*norm*abs(f);
     
   }
     /**

     * @param amp Amplitude
     */  
  BathRZ( unsigned Rm, unsigned Zm, unsigned Nz, double R_min, double Z_min, double gamma, double eddysize, double amp) : Rm_(Rm), Zm_(Zm), Nz_(Nz),R_min_(R_min), Z_min_(Z_min), gamma_(gamma), eddysize_(eddysize) , amp_(amp) {
    Rm2=(double)Rm_*(double)Rm_;
    Zm2=(double)Zm_*(double)Zm_;
    RZm= sqrt(Rm2+Zm2);

                f+= sqEkvec[z]*normalamp[z]*cos(kvec[z]*RZphasecos+normalphase[z]); 
            }      
        }
    return 1.+amp_*norm*abs(f);
    }
    else {
    return 1.;
    }
  }
  private:
