#define VIK_FEET_IN_METER 3.2808399
#define VIK_METERS_TO_FEET(X) ((X)*VIK_FEET_IN_METER)
-#define VIK_FEET_TO_METERS(X) (X/VIK_FEET_IN_METER)
+#define VIK_FEET_TO_METERS(X) ((X)/VIK_FEET_IN_METER)
+
+#define VIK_MILES_IN_METER 0.000621371192
+#define VIK_METERS_TO_MILES(X) ((X)*VIK_MILES_IN_METER)
+#define VIK_MILES_TO_METERS(X) ((X)/VIK_MILES_IN_METER)
/* MPS - Metres Per Second */
/* MPH - Metres Per Hour */
#define VIK_MPH_IN_MPS 2.23693629
-#define VIK_MPS_TO_MPH(X) (X*VIK_MPH_IN_MPS)
-#define VIK_MPH_TO_MPS(X) (X/VIK_MPH_IN_MPS)
+#define VIK_MPS_TO_MPH(X) ((X)*VIK_MPH_IN_MPS)
+#define VIK_MPH_TO_MPS(X) ((X)/VIK_MPH_IN_MPS)
/* KPH - Kilometres Per Hour */
#define VIK_KPH_IN_MPS 3.6
-#define VIK_MPS_TO_KPH(X) (X*VIK_KPH_IN_MPS)
-#define VIK_KPH_TO_MPS(X) (X/VIK_KPH_IN_MPS)
+#define VIK_MPS_TO_KPH(X) ((X)*VIK_KPH_IN_MPS)
+#define VIK_KPH_TO_MPS(X) ((X)/VIK_KPH_IN_MPS)
#define VIK_KNOTS_IN_MPS 1.94384449
-#define VIK_MPS_TO_KNOTS(X) (X*VIK_KNOTS_IN_MPS)
-#define VIK_KNOTS_TO_MPS(X) (X/VIK_KNOTS_IN_MPS)
+#define VIK_MPS_TO_KNOTS(X) ((X)*VIK_KNOTS_IN_MPS)
+#define VIK_KNOTS_TO_MPS(X) ((X)/VIK_KNOTS_IN_MPS)
#define VIK_DEFAULT_ALTITUDE 0.0
#define VIK_DEFAULT_DOP 0.0