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/* dB.c
* converts dB valuesgiven as parameters into linear ratio values
* i.e. dB 20 will give the value 10
* dB 26 will give the value 20
* dB 0 1
*/
#include <math.h>
#define db(x) pow(10,x/20.0)
main(argc,argv)
int argc;
char **argv;
{
int i,j,k,n,inv;
double x;
argc--; argv++;
for ( inv=0 ; argc; argc--, argv++) {
if (strcmp(*argv,"-i")==0) { inv=1; continue; }
x=(double)(atoi(*argv));
if (inv==0)
printf("%fdB = %f times\n",x,db(x));
else
printf("%fdB = %f times\n",20.0*log10(x),x);
}
}
/*
double db(x)
double x;
{
return(pow(10,x/20.0);
}
*/
/*
db(x)
int x;
{
int i;
static int dB_Conv[20]={
100000000, 112201845, 125892541, 141253754, 158489319,
177827941, 199526231, 223872114, 251188643, 281838293,
316227766, 354813389, 398107171, 446683592, 501187234,
562341325, 630957344, 707945784, 794328235, 891250938
};
for (i=100000000; i && x>=20; x-=20) { i/=10; }
return((i)?(dB_Conv[x]/i):-1);
}
*/
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