170 lines
3.7 KiB
C
170 lines
3.7 KiB
C
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#include <stdio.h>
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#include <stdlib.h>
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#include <math.h>
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#include "rftime.h"
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#include "rfio.h"
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struct spectrogram read_spectrogram(char *prefix,int isub,int nsub,double f0,double df0,int nbin)
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{
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int i,j,k,l,flag=0,status,msub,ibin;
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char filename[128],header[256],nfd[32];
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FILE *file;
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struct spectrogram s;
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float *z;
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int nch,j0,j1;
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double freq,samp_rate;
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float length;
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int nchan;
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// Open first file to get number of channels
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sprintf(filename,"%s_%06d.bin",prefix,isub);
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// Open file
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file=fopen(filename,"r");
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if (file==NULL) {
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printf("%s does not exist\n",filename);
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return s;
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}
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// Read header
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status=fread(header,sizeof(char),256,file);
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status=sscanf(header,"HEADER\nUTC_START %s\nFREQ %lf Hz\nBW %lf Hz\nLENGTH %f s\nNCHAN %d\n",s.nfd0,&s.freq,&s.samp_rate,&length,&nch);
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// Close file
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fclose(file);
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// Compute plotting channel
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if (f0>0.0 && df0>0.0) {
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s.nchan=(int) (df0/s.samp_rate*(float) nch);
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j0=(int) ((f0-0.5*df0-s.freq+0.5*s.samp_rate)*(float) nch/s.samp_rate);
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j1=(int) ((f0+0.5*df0-s.freq+0.5*s.samp_rate)*(float) nch/s.samp_rate);
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if (j0<0 || j1>nch)
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fprintf(stderr,"Requested frequency range out of limits\n");
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} else {
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s.nchan=nch;
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j0=0;
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j1=s.nchan;
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}
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// Number of subints
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s.nsub=nsub/nbin;
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// Allocate
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s.z=(float *) malloc(sizeof(float)*s.nchan*s.nsub);
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z=(float *) malloc(sizeof(float)*nch);
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s.mjd=(double *) malloc(sizeof(double)*s.nsub);
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s.length=(float *) malloc(sizeof(float)*s.nsub);
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// Initialize
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for (j=0;j<s.nchan*s.nsub;j++)
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s.z[j]=0.0;
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for (j=0;j<s.nsub;j++)
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s.mjd[j]=0.0;
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// Loop over files
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for (k=0,i=0,l=0,ibin=0;l<nsub;k++) {
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// Generate filename
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sprintf(filename,"%s_%06d.bin",prefix,k+isub);
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// Open file
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file=fopen(filename,"r");
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if (file==NULL) {
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printf("%s does not exist\n",filename);
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break;
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}
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printf("opened %s\n",filename);
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// Loop over contents of file
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for (;l<nsub;l++,ibin++) {
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// Read header
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status=fread(header,sizeof(char),256,file);
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if (status==0)
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break;
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status=sscanf(header,"HEADER\nUTC_START %s\nFREQ %lf Hz\nBW %lf Hz\nLENGTH %f s\nNCHAN %d\n",nfd,&freq,&samp_rate,&length,&nchan);
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s.mjd[i]+=nfd2mjd(nfd)+0.5*length/86400.0;
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s.length[i]+=length;
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// Read buffer
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status=fread(z,sizeof(float),nch,file);
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if (status==0)
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break;
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// Copy
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for (j=0;j<s.nchan;j++)
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s.z[i+s.nsub*j]+=z[j+j0];
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// Increment
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if (l%nbin==nbin-1) {
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// Scale
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s.mjd[i]/=(float) nbin;
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for (j=0;j<s.nchan;j++)
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s.z[i+s.nsub*j]/=(float) nbin;
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ibin=0;
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i++;
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}
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}
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// Close file
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fclose(file);
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}
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// Swap frequency range
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if (f0>0.0 && df0>0.0) {
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s.freq=f0;
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s.samp_rate=df0;
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}
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// Free
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free(z);
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return s;
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}
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void write_spectrogram(struct spectrogram s,char *prefix)
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{
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int i,j;
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FILE *file;
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char header[256]="",filename[256],nfd[32];
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float *z;
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double mjd;
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// Allocate
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z=(float *) malloc(sizeof(float)*s.nchan);
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// Generate filename
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sprintf(filename,"%s_%06d.bin",prefix,0);
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// Open file
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file=fopen(filename,"w");
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// Loop over subints
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for (i=0;i<s.nsub;i++) {
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// Date
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mjd=s.mjd[i]-0.5*s.length[i]/86400.0;
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mjd2nfd(mjd,nfd);
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// Generate header
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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);
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// Copy buffer
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for (j=0;j<s.nchan;j++)
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z[j]=s.z[i+s.nsub*j];
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// Dump contents
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fwrite(header,sizeof(char),256,file);
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fwrite(z,sizeof(float),s.nchan,file);
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}
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// Close file
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fclose(file);
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// Free
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free(z);
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return;
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}
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