#include <math.h>
#include "calc_mag.h"

double calc_ms (double amplitude, double frequency, Station_Struct sta_info, double lat, double lon) {

  double period=1/frequency;
  double correction=(20-period) * 0.02;
  double delta=calc_dist(sta_info.lat,sta_info.lon,lat,lon);
  double ms;

  if (17<period<23) {
    ms=log10(amplitude)+1.66*log10(delta)+2.0+correction;
  } else {
    fprintf(stderr,"Bad period %lf for Ms\n",period);
    ms=-1;
  }
  
  return ms;
}