**********************************************************************/
typedef int64_t vrt_freq_t;
#define VRT_FREQ_RP 20
-#define VRT_FREQ_C(_x) _FXPT_C(vrt_altitude_t, _x, VRT_FREQ_RP)
+#define VRT_FREQ_C(_x) _FXPT_C(vrt_freq_t, _x, VRT_FREQ_RP)
static inline vrt_freq_t
double_to_vrt_freq(double num){