/* dbtopower.c  given integer db, compute power ratio */
/*              voltage ratio is sqrt of power ratio  */
/* db = 10 log10(power1/power2)  or when power2 = 1.0 */
/* power = 10**(db/10)                                */

#include <stdio.h>
#include <math.h>
#include <stdlib.h>

int main(int argc, char * argv[])
{
  int i;
  double db, power, v;

  printf("db to power.c running \n");
  printf("db = 10 * log10(power2 / power1) \n");
  for(i=-20; i<=20; i++)
  {
    db = (double)i;
    power = pow(10.0,db/10.0);
    v = sqrt(power);
    printf("%3d db is power ratio %f, voltage ratio %f \n", i, power, v);
  }
  printf(" \n");
  printf("60 db - 40 db increase of 20 db, power increase of 100 \n");
  db = 10.0*log10(100.0/1.0);
  printf("db = 10.0*math.log10(100.0/1.0) = %f\n", db);

  return 0;
} /* end dbtopower.c */