ref: b64d8dc0823fba431eca1474fdc8c54bb4f14eb9
dir: /test/corr.c/
/* corr.c print correlation coeff's for 2 input files of 'short' values Copyright (C) 1999 Stanley J. Brooks <stabro@megsinet.net> This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include <string.h> // for open,read,write: #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <errno.h> #include <unistd.h> // for clock/time: #include <time.h> #include <stdlib.h> #include <stdio.h> #include <math.h> #define BLEN 0x20000 #define HLEN 0x1000 static u_int32_t dist[0x10000]; #define dis0 (dist+0x8000) static short buff1[BLEN]; static short buff2[BLEN]; static short hist[HLEN]; inline static double square(double x) {return (x*x);} static void readin(int fd, short *p, int bs) { int r; do { r=read(fd,(char*)p,2*bs); }while (r==-1 && errno==EINTR); if (r==-1 || r!=2*bs) { perror("Input error"); exit(1); } } int main(int argct, char **argv) { int fd1,fd2; int avgn=0,assay=0,code=0; int hx=0,hsum=0; int len,len1,len2,x,r; char *fnam1,*fnam2; double v1=0,v2=0,s1=0; /* * Parse the command line arguments */ while (*++argv && **argv == '-') while (*(++*argv)) switch (**argv) { case 'a': assay=1; break; case 'c': code=1; break; case 'h': fprintf(stderr,"./stat [-n avgn] <file>\n"); break; case 'n': if (!*++*argv) { // end of this param string if (!argv[1]) break; ++argv; } avgn=atoi(*argv); *argv += strlen(*argv)-1; // skip to end-1 of this param string break; } if (avgn<=0) avgn=1; else if (avgn>HLEN) avgn=HLEN; bzero(hist,sizeof(hist)); fnam1=*argv++; fd1=open(fnam1,O_RDWR); if (fd1<0) { fprintf(stderr,"Open: %s %s\n",fnam1,strerror(errno)); return(1); } len1=lseek(fd1,0,SEEK_END); r=lseek(fd1,0,SEEK_SET); fnam2=*argv++; fd2=open(fnam2,O_RDWR); if (fd2<0) { fprintf(stderr,"Open: %s %s\n",fnam2,strerror(errno)); return(1); } len2=lseek(fd2,0,SEEK_END); r=lseek(fd2,0,SEEK_SET); bzero(dist,sizeof(dist)); len = (len1<len2)? len1:len2; len /= 2; /* now len is number of shorts data to read */ for (x=0; x<len; ){ int bs; int j; double c11=0, c12=0, c22=0; bs=len-x; if (bs>BLEN) bs=BLEN; /* number of shorts to read */ readin(fd1,buff1,bs); readin(fd2,buff2,bs); for (j=0; j<bs; j++) { c11 += buff1[j]*buff1[j]; c12 += buff1[j]*buff2[j]; c22 += buff2[j]*buff2[j]; } c11 /= bs; c12 /= bs; c22 /= bs; { double d11=(c11+2*c12+c22)/4; double d22=(c11-2*c12+c22)/4; double d12=(c11-c22)/4; printf("%8.1f%8.1f cf=%f",sqrt(c11),sqrt(c22),c12/sqrt(c11*c22)); printf(" | %8.1f%8.1f cf=%f\n",sqrt(d11),sqrt(d22),d12/sqrt(d11*d22)); } for (j=0; j<bs; j++) { int y; //y=(abs(buff1[j])<abs(buff2[j]))? buff1[j]:buff2[j]; y=(buff1[j]+buff2[j]+1)/2; hsum -= hist[hx]; hsum += y; hist[hx] = y; if (++hx == avgn) hx=0; s1 += abs(y); v1 += hsum; v2 += square(hsum); y = (hsum+avgn/2)/avgn; dis0[y]++; } x += bs; } v1 /= len; v2 /= len; printf("%8d %5d=n %10.2f=avg %10.2f=rms\n",len,avgn,v1/avgn,sqrt(v2-v1*v1)/avgn); if (code) { int32_t j,tot,cut; cut = len/2; for (tot=0,j=0; j<0x8000; j++) { int32_t tot1; tot1 = tot+dis0[j]; if (j!=0) tot1 += dis0[-j]; if (tot1>cut && tot<=cut) { printf(" |%d| %d of %d\n",j-1,tot,cut); cut += (len-cut)/2; } tot=tot1; } } if (assay) for (x=-0x8000; x<=0x7fff; x++) { printf("%6d %6d\n",x,dis0[x]); } return 0; }