if scaling = 0 then don't change vect. length

Author: matthew-hennefarth

source/matplot/axes_objects/vectors.cpp

@@ -147,9 +147,14 @@ namespace matplot {
                         std::sqrt(u_value * u_value + v_value * v_value +
                                   w_value * w_value);
                     if (mag != 0.0) {
-                        u_value *= scale_ / mag;
-                        v_value *= scale_ / mag;
-                        w_value *= scale_ / mag;
+                        u_value /= mag;
+                        v_value /= mag;
+                        w_value /= mag;
+                    }
+                    if (scale_ != 0.0) {
+                        u_value *= scale_;
+                        v_value *= scale_;
+                        w_value *= scale_;
                     }
                 }