C/C++ Interactive Reference Guide/C-C++ Interactive Reference Guide.iso/c_ref/csource3/187_01/vbar.c

C/C++ Source or Header | 1986-01-21 | 4.6 KB | 161 lines

/*@******************************************************************
 *@
 *@  VBAR generates a vertical bar graph from a pair of vectors.
 *@
 *@  vbar(x, y, num, title, xtitle, ytitle, maxrows, maxcols, xdec, ydec)
 *@
 *@ where:
 *@        x         - vector of x coordinates
 *@        y         - vector of y coordinates
 *@        num     - number of elements in both x and y
 *@        title    - graph title (printed at top of page)
 *@        xtitle    - title of x coordinate (printed at bottom-horizontal)
 *@        ytitle    - title of y coordinate (printed at left side-horizontally)
 *@        maxrows - maximum number of y lines to be printed
 *@        maxcols - maximum number of x lines to be printed
 *@        xdec    - number of decimal places in x values
 *@        ydec    - number of decimal places in y values
 *@
 *@******************************************************************** */


#define    YTICKW    16            /* y tick width */

int vbar(x, y, num, title, xtitle, ytitle, maxrows, maxcols, xdec, ydec)
int *x, *y, num, maxrows, maxcols, xdec, ydec;
char *title, *xtitle, *ytitle;
{
    char mytitle[80], pad[80], c[2], strbuf[80];
    char *r_just(), *itoa(), *c_just(), *p, *mak_dec();
    int i, j, xmax, xmin, ymax, ymin, xinc, yinc;
    int xbuck, xbuckv, ybuck, ybuckv, yval, xrange, yrange;
    int gutter, xwide, ywide, temp, k, lower, upper, r, l;

    gutter = 1;        /* dist between bars */
    maxcols -= YTICKW;    /* subtract y-tick width */
    xmax = xmin = x[0];
    ymax = ymin = y[0];

    for (i=0; i < num; i++) {    /* determine x and y data ranges */
        if (xmax < x[i])
            xmax = x[i];
        if (ymax < y[i])
            ymax = y[i];
        if (xmin > x[i])
            xmin = x[i];
        if (ymin > y[i])
            ymin = y[i];
    }

    /* compute the x and y bucket sizes */
    xrange = xmax - xmin;
    yrange = ymax - ymin;
    for (i=1; i < (maxcols - 2); i++) {
        xbuck = maxcols / (gutter + i);        /* i is size of one bucket */
        xinc = (xrange + xbuck - 1) / xbuck;
        if (xinc >= 1)            /* continue until you fill the avail space */
            break;
    }
    xwide = i;
    if (xinc < 1) {
        xbuck = maxcols / (gutter + 1);
        xinc = 1;
    }
    else
        xbuck = (xrange + xinc - 1) / xinc;        /* readjust buckets, if necessary */

    for (i=1; i < maxrows; i++) {
        ybuck = maxrows / i;
        yinc = (yrange + ybuck - 1) / ybuck;
        if (yinc >= 1)
            break;
    }
    ywide = i;
    if (yinc < 1) {
        ybuck = maxrows;
        yinc = 1;
    }
    else
        ybuck = (yrange + yinc - 1) / yinc;        /* readjust buckets, if necessary */


    /* compute pad on left of graph to center graph horizontally */
    temp = maxcols - xbuck * (xwide + gutter);
    for (i=0; i < temp;)
        pad[i++] = ' ';
    pad[i] = '\0';

    /* print the graph title at the top  */
    puts("\n\n\n");
    for (i=0; i < YTICKW; i++)
        puts(" ");
    puts(c_just(title, xbuck * (gutter + xwide)));
    puts("\n\n");

    /* print the y-axis title at the left of the page */
    puts("    ");
    puts(ytitle);
    puts("\n");

    /* draw the chart */
    c[1] = '\0';    /* set EOS */
    for (i=0; i < ybuck; i++) {    /* once per line (y buckets) */
        yval = ymax - (i * yinc);
        puts("\n  ");
        puts(r_just(mak_dec(itoa(yval, strbuf), ydec), 10));
        puts("  |");
        for (j=1; j <= xbuck; j++) {    /* once per column (x buckets) */
            temp = 0;
            lower = (j-1) * xinc;        /* compute proper x-range */
            upper = lower + xinc;
            r = 0;
            for (k=0; k < num; k++)        /* sum all y values in this x-range */
                if ((x[k] > lower) && (x[k] <= upper)) {
                    temp += y[k];
                    r++;        /* indicate that at least one was found */
                }
            if ((temp >= yval) && r)     /* if in range and at least one hit */
                c[0] = '*';
            else
                c[0] = ' ';
            for (k=0; k < gutter; k++)
                puts(" ");
            for (k=0; k < xwide; k++)
                puts(c);
        }
    }
    puts("\n");

    /* print the x-scale */
    puts("              |\b__");    /* skip to start of Y axis */
    for (i=0; i <= xbuck; i++)
        for (k=0; k < (gutter + xwide); k++)
            puts("_");
    puts("\n");
    for (i=1; i < YTICKW; i++)    /* skip to start of Y axis */
        puts(" ");
    temp = xinc + xmin;
    while (temp <= xmax)
        for (r=1; r > 0; r++, temp += xinc) {
            itoa(temp, strbuf);
            if (xdec)            /* suppress decimal point if zero decimal places */
                l = strlen(p = mak_dec(strbuf, xdec));    /* make value a string */
            else
                l = strlen(p = strbuf);    /* make value a string */
            i = r * (gutter + xwide);
/*            printf("r=%d, temp=%d, l=%d, i=%d\n", r, temp, l, i);  */
            if ((i / (l + 1)) >= 1) {    /* does it fit? */
                puts(r_just(p, i));        /* yes, output it */
                r = -1;                    /* .. and quit trying */
            }
        }

    puts("\n");
    for (i=0; i < YTICKW; i++)
        puts(" ");
    puts(c_just(xtitle, xbuck * (gutter + xwide)));
    puts("\n");
}