/* filt.c       Joe Mietus      Apr 1 2011 */

/* filt.c       Joe Mietus      Oct 7 2008 */

/* getline renamed to lineget May 18 2010 */

/*

filt :

Usage: filt filt hwin [options]

  Reads 1 (y) or 2 (x,y) columns from stdin and

  filters outliers by deleting those intervals outside

  of `filt' range of the average within a window

  `hwin' distance on either side of the

  current interval.

  options are :

  [-x min max] : exclude date outside min - max

  [-n] : print ratio of nout to nin

  [-p file] : print excluded points to file

              not including start/end hwin buffer

  excluded points may not be printed in time

  sequential order if -x opption is used

*/

#include <stdio.h>

#include <stdlib.h>

#include <math.h>

#define MAXSTR 256

#define MAXWIN 1024

char *prog, line[MAXSTR], tmp[MAXSTR];

int ncols;

static double x[MAXWIN+1], y[MAXWIN+1];

FILE *fp;

main(argc, argv)

int argc;

char * argv[];

{

    int hwin, win, i, j, k, nin, nout;

    int xflag, nflag, pflag;

    double filt, filtmin, filtmax, min, max, mtmp, sum, av;

    xflag = 0;

    nflag = pflag = nin = nout = 0;

    sum = 0.0;

    prog = argv[0];

    if (argc < 3) {

        usage();

    exit(1);

    }

    i = 1;

    if ((filt = atof(argv[i])) <= 0) {

            fprintf(stderr, "%s: filt must be greater than 0\n",

                    prog);

            exit(2);

    }

    if ((hwin = atoi(argv[++i])) <= 0) {

            fprintf(stderr, "%s: hwin must be integer greater than 0\n",

                    prog);

            exit(2);

    }

    if ((win = 2*hwin) > MAXWIN) {

            fprintf(stderr, "%s: max hwin = %d\n", prog, MAXWIN/2);

            exit(2);

    }

    for ( ; ++i < argc && *argv[i] == '-'; ) {

        switch(argv[i][1]) {

            case 'x': if (i+3 > argc) {

                      usage();

              exit(1);

              }

                  min = atof(argv[++i]);

                  max = atof(argv[++i]);

                      if (min > max) {

                  mtmp = min;

              min = max;

              max = mtmp;

                      }

                  xflag = 1;

                      break;

            case 'n': nflag = 1;

                      break;

            case 'p': if ((fp = fopen(argv[++i], "w")) == NULL)

                      fprintf(stderr, "%s : Can't open %s\n",

                  argv[0], argv[i]);

              else

              pflag = 1;

                      break;

            default:  usage();

                      exit(1);

        }

    }

    i = 0;

    if (fgets(line, MAXSTR, stdin) == NULL) {

    fprintf(stderr, "%s : no data read\n", prog);

    exit(2);

    }

    if (sscanf(line, "%lf %lf %s", &x[i], &y[i], tmp) == 3) {

    fprintf(stderr, "%s : incorrectly formatted data\n", prog);

    exit(2);

    }

    else if (sscanf(line, "%lf %lf", &x[i], &y[i]) == 2) {

        ncols = 2;

    }

    else if (sscanf(line, "%lf %s", &x[i], tmp) == 2) {

    fprintf(stderr, "%s : incorrectly formatted data\n", prog);

    exit(2);

    }

    else if (sscanf(line, "%lf", &y[i]) == 1) {

        ncols = 1;

    x[0] = 0;

    }

    else {

    fprintf(stderr, "%s : incorrectly formatted data\n", prog);

    exit(2);

    }

    nin++;

    if (pflag)

        fprintline(i);

    i++;

    while (i<=win) {

        if (lineget(i) == EOF) {

        fprintf(stderr, "%s : insufficient data\n", prog);

            exit(2);

    }

        nin++;

        if (xflag && (y[i]<min || y[i]>max)) {

        if (pflag)

            fprintline(i);

        }

        else {

            if (pflag && i<hwin)

            fprintline(i);

            i++;

        }

    }

    i = 0;

    j = hwin;

    for (i=0; i<=win; i++)

        sum += y[i];

    sum -= y[j];

    av = sum/win;

    sum += y[j] - y[0];

    filtmax = filtmin = filt * av;

    if (y[j] <= av+filtmax && y[j] >= av-filtmin) {

        printline(j);

        nout++;

    }

    else if (pflag)

        fprintline(j);

    i = 0;

    while (lineget(i) != EOF) {

        nin++;

    if (xflag && (y[i]<min || y[i]>max)) {

        if (pflag)

                fprintline(i);

    }

        else {

            if (++j > win)

                j = 0;

            sum += y[i] - y[j];

        av = sum/win;

            if (++i > win)

                i = 0;

        sum += y[j] - y[i];

            filtmax = filtmin = filt * av;

            if (y[j] <= av+filtmax && y[j] >= av-filtmin) {

            printline(j);

                nout++;

            }

        else {

            if (pflag)

                    fprintline(j);

            }

    }

    }

    if (pflag) {

        for (i=0; i<hwin; i++) {

            if (++j > win)

                j = 0;

            fprintline(j);

    }

    }

    if (nflag)

        fprintf(stderr, "nout : nin = %d : %d = %g\n", 

        nout, nin, (double)nout/nin);

    exit(0);

}

lineget(i)

int i;

{

    int j;

    static int n = 1;

    if (fgets(line, MAXSTR, stdin) == NULL)

        return(EOF);

    if (ncols == 1) {

        if ((j = sscanf(line, "%lf %s", &y[i], tmp)) != 1) {

            fprintf(stderr, "%s: incorrectly formatted data : ", prog);

        fprintf(stderr, "line = %d\n", n+1);

        exit(2);

        }

    x[i] = n;

    }

    else if (ncols == 2) {

        if ((j = sscanf(line, "%lf %lf %s", &x[i], &y[i], tmp)) != 2) {

            fprintf(stderr, "%s: incorrectly formatted data : ", prog);

        fprintf(stderr, "line = %d\n", n+1);

        exit(2);

        }

    }

    n++;

    return(j);

}

printline(i)

int i;

{

    if (ncols == 2)

        printf("%.9g ", x[i]);

    printf("%g\n", y[i]);

}

fprintline(i)

int i;

{

    if (ncols == 2)

        fprintf(fp, "%.9g ", x[i]);

    fprintf(fp, "%g\n", y[i]);

}

usage()

{

    fprintf(stderr, "Usage: %s filt hwin [options]\n", prog);

    fprintf(stderr, " Reads 1 (y) or 2 (x,y) columns from stdin and\n");

    fprintf(stderr, " filters outliers by deleting those intervals outside\n");

    fprintf(stderr, " of `filt' range of the average within a window\n");

    fprintf(stderr, " `hwin' distance on either side of the\n");

    fprintf(stderr, " current interval.\n\n");

    fprintf(stderr, " options are :\n");

    fprintf(stderr, " [-x min max] : exclude date outside min - max\n");

    fprintf(stderr, " [-n] : print ratio of nout to nin\n");

    fprintf(stderr, " [-p file] : print excluded points to file\n");

    fprintf(stderr, "             not including start/end hwin buffer\n");

    fprintf(stderr, " excluded points may not be printed in time\n");

    fprintf(stderr, " sequential order if -x opption is used\n");

}