mirror of
git://projects.qi-hardware.com/ben-wpan.git
synced 2024-11-23 04:23:10 +02:00
e445fe1b01
- usrp/d.c: reduce the number of data points in a file produced by usrp2_rx_cfile.py and print them as text suitable for gnuplot - usrp/p.c: determine the peak amplitude in a series of transmissions, filtering noise and artefacts at the beginning of the data file - usrp/step: step through all channels and measure TX power (for antenna tuning) - usrp/Makefile: built "p" and "d"
67 lines
1006 B
C
67 lines
1006 B
C
#include <stdlib.h>
|
|
#include <stdio.h>
|
|
#include <math.h>
|
|
#include <sys/types.h>
|
|
|
|
|
|
#define PERC 0.9
|
|
#define SKIP 1000000
|
|
|
|
|
|
static int comp(const void *_a, const void *_b)
|
|
{
|
|
float a = *(const float *) _a;
|
|
float b = *(const float *) _b;
|
|
|
|
return a < b ? -1 : a > b;
|
|
}
|
|
|
|
|
|
int main(int argc, char **argv)
|
|
{
|
|
float max = 0;
|
|
float c[2], a;
|
|
float *rec = NULL;
|
|
int e = 0, n = 0, skip = SKIP;
|
|
|
|
while (1) {
|
|
size_t s;
|
|
|
|
s = fread(c, sizeof(c), 1, stdin);
|
|
if (!s) {
|
|
if (!ferror(stdin))
|
|
break;
|
|
if (s < 0) {
|
|
perror("read");
|
|
return 1;
|
|
}
|
|
}
|
|
if (skip) {
|
|
skip--;
|
|
continue;
|
|
}
|
|
a = hypotf(c[0], c[1]);
|
|
if (a > max)
|
|
max = a;
|
|
if (e <= n) {
|
|
e = e ? e*2 : 10000;
|
|
rec = realloc(rec, e*sizeof(float));
|
|
if (!rec) {
|
|
perror("realloc");
|
|
exit(1);
|
|
}
|
|
}
|
|
rec[n] = a;
|
|
n++;
|
|
}
|
|
qsort(rec, n, sizeof(float), comp);
|
|
printf("%f %f\n", max, rec[(int) (PERC*n)]);
|
|
#if 0
|
|
int i;
|
|
|
|
for (i = 0; i < n; i += 1000)
|
|
printf("%f %f\n", (double) i/n, rec[i]);
|
|
#endif
|
|
return 0;
|
|
}
|