strf/rfio.c

253 lines
6.0 KiB
C

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <math.h>
#include "rftime.h"
#include "rfio.h"
struct spectrogram read_spectrogram(char *prefix,int isub,int nsub,double f0,double df0,int nbin,double foff)
{
int i,j,k,l,flag=0,status,msub,ibin,nadd,nbits=-32;
char filename[128],header[256],nfd[32];
FILE *file;
struct spectrogram s;
float *z,zavg,zstd;
char *cz;
int nch,j0,j1;
double freq,samp_rate;
float length;
int nchan,dummy;
float s1,s2;
// Open first file to get number of channels
sprintf(filename,"%s_%06d.bin",prefix,isub);
// Open file
file=fopen(filename,"r");
if (file==NULL) {
printf("%s does not exist\n",filename);
s.nsub=0;
return s;
}
// Read header
status=fread(header,sizeof(char),256,file);
if (strstr(header,"NBITS 8")==NULL) {
status=sscanf(header,"HEADER\nUTC_START %s\nFREQ %lf Hz\nBW %lf Hz\nLENGTH %f s\nNCHAN %d\nNSUB %d\n",s.nfd0,&s.freq,&s.samp_rate,&length,&nch,&msub);
} else {
status=sscanf(header,"HEADER\nUTC_START %s\nFREQ %lf Hz\nBW %lf Hz\nLENGTH %f s\nNCHAN %d\nNSUB %d\nNBITS 8\nMEAN %f\nRMS %f",s.nfd0,&s.freq,&s.samp_rate,&length,&nch,&dummy,&zavg,&zstd);
nbits=8;
}
s.freq+=foff;
// Close file
fclose(file);
// Compute plotting channel
if (f0>0.0 && df0>0.0) {
s.nchan=(int) (df0/s.samp_rate*(float) nch);
j0=(int) ((f0-0.5*df0-s.freq+0.5*s.samp_rate)*(float) nch/s.samp_rate);
j1=(int) ((f0+0.5*df0-s.freq+0.5*s.samp_rate)*(float) nch/s.samp_rate);
if (j0<0 || j1>nch) {
fprintf(stderr,"Requested frequency range out of limits\n");
s.nsub=0;
s.nchan=0;
return s;
}
} else {
s.nchan=nch;
j0=0;
j1=s.nchan;
}
// Read whole file if not specified
if (nsub==0 && msub>0)
nsub=msub;
// Number of subints
s.nsub=nsub/nbin;
// Allocate
s.z=(float *) malloc(sizeof(float)*s.nchan*s.nsub);
s.zavg=(float *) malloc(sizeof(float)*s.nsub);
s.zstd=(float *) malloc(sizeof(float)*s.nsub);
z=(float *) malloc(sizeof(float)*nch);
cz=(char *) malloc(sizeof(char)*nch);
s.mjd=(double *) malloc(sizeof(double)*s.nsub);
s.length=(float *) malloc(sizeof(float)*s.nsub);
// Initialize
for (j=0;j<s.nchan*s.nsub;j++)
s.z[j]=0.0;
for (j=0;j<s.nsub;j++)
s.mjd[j]=0.0;
// Loop over files
for (k=0,i=0,l=0,ibin=0,nadd=0;l<nsub;k++) {
// Generate filename
sprintf(filename,"%s_%06d.bin",prefix,k+isub);
// Open file
file=fopen(filename,"r");
if (file==NULL) {
printf("%s does not exist\n",filename);
s.nsub=nsub;
break;
}
printf("opened %s\n",filename);
// Loop over contents of file
for (;l<nsub;l++,ibin++) {
// Read header
status=fread(header,sizeof(char),256,file);
if (status==0)
break;
if (nbits==-32)
status=sscanf(header,"HEADER\nUTC_START %s\nFREQ %lf Hz\nBW %lf Hz\nLENGTH %f s\nNCHAN %d\nNSUB %d\n",nfd,&freq,&samp_rate,&length,&nchan,&msub);
else if (nbits==8)
status=sscanf(header,"HEADER\nUTC_START %s\nFREQ %lf Hz\nBW %lf Hz\nLENGTH %f s\nNCHAN %d\nNSUB %d\nNBITS 8\nMEAN %f\nRMS %f",nfd,&freq,&samp_rate,&length,&nchan,&dummy,&zavg,&zstd);
s.mjd[i]+=nfd2mjd(nfd)+0.5*length/86400.0;
s.length[i]+=length;
nadd++;
// Read buffer
if (nbits==-32) {
status=fread(z,sizeof(float),nch,file);
} else if (nbits==8) {
status=fread(cz,sizeof(char),nch,file);
for (j=0;j<nch;j++)
z[j]=6.0/256.0*(float) cz[j]*zstd+zavg;
}
if (status==0)
break;
// Copy
for (j=0;j<s.nchan;j++)
s.z[i+s.nsub*j]+=z[j+j0];
// Increment
if (l%nbin==nbin-1) {
// Scale
s.mjd[i]/=(float) nadd;
for (j=0;j<s.nchan;j++)
s.z[i+s.nsub*j]/=(float) nadd;
ibin=0;
nadd=0;
i++;
}
}
// Close file
fclose(file);
}
// Scale last subint
if(nadd>0)
{
s.mjd[i]/=(float) nadd;
for (j=0;j<s.nchan;j++)
s.z[i+s.nsub*j]/=(float) nadd;
}
// Swap frequency range
if (f0>0.0 && df0>0.0) {
s.freq=f0;
s.samp_rate=df0;
}
// Compute averages
for (i=0;i<s.nsub;i++) {
s.zavg[i]=0.0;
for (j=0;j<s.nchan;j++)
if (!isnan(s.z[i+s.nsub*j]) && !isinf(s.z[i+s.nsub*j]))
s.zavg[i]+=s.z[i+s.nsub*j];
s.zavg[i]/=(float) s.nchan;
}
// Compute deviations
for (i=0;i<s.nsub;i++) {
s.zstd[i]=0.0;
for (j=0;j<s.nchan;j++)
if (!isnan(s.z[i+s.nsub*j]) && !isinf(s.z[i+s.nsub*j]))
s.zstd[i]+=pow(s.zavg[i]-s.z[i+s.nsub*j],2);
s.zstd[i]=sqrt(s.zstd[i]/(float) s.nchan);
}
// Compute limits
for (i=0;i<s.nsub;i++) {
if (i==0) {
s.zmin=s.zavg[i]-1.0*s.zstd[i];
s.zmax=s.zavg[i]+1.0*s.zstd[i];
} else {
if (s.zavg[i]-1.0*s.zstd[i]<s.zmin) s.zmin=s.zavg[i]-1.0*s.zstd[i];
if (s.zavg[i]+1.0*s.zstd[i]>s.zmax) s.zmax=s.zavg[i]+1.0*s.zstd[i];
}
}
// Free
free(z);
free(cz);
return s;
}
void write_spectrogram(struct spectrogram s,char *prefix)
{
int i,j;
FILE *file;
char header[256]="",filename[256],nfd[32];
float *z;
double mjd;
// Allocate
z=(float *) malloc(sizeof(float)*s.nchan);
// Generate filename
sprintf(filename,"%s_%06d.bin",prefix,0);
// Open file
file=fopen(filename,"w");
// Loop over subints
for (i=0;i<s.nsub;i++) {
// Date
mjd=s.mjd[i]-0.5*s.length[i]/86400.0;
mjd2nfd(mjd,nfd);
// Generate header
sprintf(header,"HEADER\nUTC_START %s\nFREQ %lf Hz\nBW %lf Hz\nLENGTH %f s\nNCHAN %d\nEND\n",nfd,s.freq,s.samp_rate,s.length[i],s.nchan);
// Copy buffer
for (j=0;j<s.nchan;j++)
z[j]=s.z[i+s.nsub*j];
// Dump contents
fwrite(header,sizeof(char),256,file);
fwrite(z,sizeof(float),s.nchan,file);
}
// Close file
fclose(file);
// Free
free(z);
return;
}
void free_spectrogram(struct spectrogram s)
{
free(s.z);
free(s.zavg);
free(s.zstd);
free(s.mjd);
free(s.length);
}