void get_chan_stats(struct psrfits *pfi, struct subband_info *si){
int ii;
double avg, std;
for (ii = 0 ; ii < si->bufwid ; ii++) {
// Only use 1/8 of the total length in order to speed things up
avg_std(pfi->sub.fdata + ii, si->buflen / 8, &avg, &std, si->bufwid);
//printf("%d %f %f\n", ii, avg, std);
si->chan_avgs[ii] = avg;
si->chan_stds[ii] = std;
}
}
void print_raw_chan_stats(unsigned char *data, int nspect, int nchan, int npol){
int ii, jj;
double avg, std;
float *tmparr;
tmparr = (float *)malloc(sizeof(float) * nspect);
for (ii = 0 ; ii < nchan ; ii++) {
// Grab the raw data
for (jj = 0 ; jj < nspect ; jj++)
tmparr[jj] = (float)data[npol * nchan * jj + ii];
avg_std(tmparr, nspect, &avg, &std, 1);
printf("%4d: %10.3f %10.3f\n", ii, avg, std);
}
free(tmparr);
}
void new_scales_and_offsets(struct psrfits *pfo, int numunsigned) {
int ii, poln;
double avg, std;
const int nspec = pfo->hdr.nsblk / pfo->hdr.ds_time_fact;
const int nchan = pfo->hdr.nchan / pfo->hdr.ds_freq_fact;
const int npoln = (pfo->hdr.onlyI) ? 1 : pfo->hdr.npol;
const int bufwid = npoln * nchan;
const float target_std = 20.0; // This is reasonable for 8-bit data
for (poln = 0 ; poln < npoln ; poln++) {
float target_avg = (poln < numunsigned) ? 128.0 : 0.0;
float *out_scls = pfo->sub.dat_scales + poln * nchan;
float *out_offs = pfo->sub.dat_offsets + poln * nchan;
for (ii = 0 ; ii < nchan ; ii++) {
float *fptr = pfo->sub.fdata + poln * nchan + ii;
avg_std(fptr, nspec, &avg, &std, bufwid);
out_scls[ii] = std / target_std;
out_offs[ii] = avg - (target_avg * out_scls[ii]);
}
}
}
void new_scales_and_offsets(struct psrfits *pfo, int numunsigned, Cmdline *cmd) {
int ii, poln;
double avg, std;
const int nspec = pfo->hdr.nsblk / pfo->hdr.ds_time_fact;
const int nchan = pfo->hdr.nchan / pfo->hdr.ds_freq_fact;
const int npoln = (pfo->hdr.onlyI) ? 1 : pfo->hdr.npol;
const int bufwid = npoln * nchan;
// Target avg is for unsigned; defaults to 0
float target_avg = cmd->tgtavg, target_std = cmd->tgtstd;
float *avgs = NULL, *stds = NULL;
if (cmd->tgtstd == 0.0) {
// Set these to give ~6-sigma of total gaussian
// variation across the full range of values
// The numerator is (256.0, 16.0, 4.0) for (8, 4, 2) bits
target_std = (1 << pfo->hdr.nbits) / 6.0;
}
if (cmd->tgtavg == 0.0) {
// Set these slightly below the midpoints to
// allow us more headroom for RFI
// The 1st term is (127.5, 7.5, 1.5) for (8, 4, 2) bits
target_avg = ((1 << (pfo->hdr.nbits - 1)) - 0.5) \
- 1.0 * target_std;
}
if (cmd->bandpassfileP) {
int N;
printf("Overriding input channel statistics with those in '%s'\n",
cmd->bandpassfile);
read_bandpass(pfo, cmd->bandpassfile, &N, &avgs, &stds);
if (N != nchan) {
printf("Error!: Problem reading %d bandpass from '%s'\n\n",
N, cmd->bandpassfile);
exit(-1);
}
} else {
avgs = (float *)malloc(nchan * sizeof(float));
stds = (float *)malloc(nchan * sizeof(float));
}
for (poln = 0 ; poln < npoln ; poln++) {
float tgtavg = (poln < numunsigned) ? target_avg : 0.0;
float *out_scls = pfo->sub.dat_scales + poln * nchan;
float *out_offs = pfo->sub.dat_offsets + poln * nchan;
if (!cmd->bandpassfileP) {
for (ii = 0 ; ii < nchan ; ii++) {
float *fptr = pfo->sub.fdata + poln * nchan + ii;
avg_std(fptr, nspec, &avg, &std, bufwid);
avgs[ii] = avg;
stds[ii] = std;
}
}
for (ii = 0 ; ii < nchan ; ii++) {
out_scls[ii] = stds[ii] / target_std;
out_offs[ii] = avgs[ii] - (tgtavg * out_scls[ii]);
}
}
free(avgs);
free(stds);
}
