예제 #1
0
static void
do_bezier(
    struct curve_points *cp,
    double *bc,			/* Bezier coefficient array */
    int first_point,		/* where to start in plot->points */
    int num_points,		/* to determine end in plot->points */
    struct coordinate *dest)	/* where to put the interpolated data */
{
    int i;
    coordval x, y;

    /* min and max in internal (eg logged) co-ordinates. We update
     * these, then update the external extrema in user co-ordinates
     * at the end.
     */

    double ixmin, ixmax, iymin, iymax;
    double sxmin, sxmax, symin, symax;	/* starting values of above */

    x_axis = cp->x_axis;
    y_axis = cp->y_axis;

    ixmin = sxmin = X_AXIS.min;
    ixmax = sxmax = X_AXIS.max;
    iymin = symin = Y_AXIS.min;
    iymax = symax = Y_AXIS.max;

    for (i = 0; i < samples_1; i++) {
	eval_bezier(cp, first_point, num_points,
		    (double) i / (double) (samples_1 - 1),
		    &x, &y, bc);

	/* now we have to store the points and adjust the ranges */

	dest[i].type = INRANGE;
	STORE_AND_FIXUP_RANGE(dest[i].x, x, dest[i].type, ixmin, ixmax, X_AXIS.autoscale);
	STORE_AND_FIXUP_RANGE(dest[i].y, y, dest[i].type, iymin, iymax, Y_AXIS.autoscale);

	dest[i].xlow = dest[i].xhigh = dest[i].x;
	dest[i].ylow = dest[i].yhigh = dest[i].y;

	dest[i].z = -1;
    }

    UPDATE_RANGE(ixmax > sxmax, X_AXIS.max, ixmax);
    UPDATE_RANGE(ixmin < sxmin, X_AXIS.min, ixmin);
    UPDATE_RANGE(iymax > symax, Y_AXIS.max, iymax);
    UPDATE_RANGE(iymin < symin, Y_AXIS.min, iymin);
}
예제 #2
0
static void
do_freq(
    struct curve_points *plot,	/* still contains old plot->points */
    int first_point,		/* where to start in plot->points */
    int num_points)		/* to determine end in plot->points */
{
    double x, y;
    int i;
    int x_axis = plot->x_axis;
    int y_axis = plot->y_axis;
    struct coordinate GPHUGE *this;

    /* min and max in internal (eg logged) co-ordinates. We update
     * these, then update the external extrema in user co-ordinates
     * at the end.
     */

    double ixmin, ixmax, iymin, iymax;
    double sxmin, sxmax, symin, symax;	/* starting values of above */

    ixmin = sxmin = X_AXIS.min;
    ixmax = sxmax = X_AXIS.max;
    iymin = symin = Y_AXIS.min;
    iymax = symax = Y_AXIS.max;

    this = (plot->points) + first_point;

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

	x = this[i].x;
	y = this[i].y;

	this[i].type = INRANGE;

	STORE_AND_FIXUP_RANGE(this[i].x, x, this[i].type, ixmin, ixmax, X_AXIS.autoscale);
	STORE_AND_FIXUP_RANGE(this[i].y, y, this[i].type, iymin, iymax, Y_AXIS.autoscale);

	this[i].xlow = this[i].xhigh = this[i].x;
	this[i].ylow = this[i].yhigh = this[i].y;
	this[i].z = -1;
    }

    UPDATE_RANGE(ixmax > sxmax, X_AXIS.max, ixmax);
    UPDATE_RANGE(ixmin < sxmin, X_AXIS.min, ixmin);
    UPDATE_RANGE(iymax > symax, Y_AXIS.max, iymax);
    UPDATE_RANGE(iymin < symin, Y_AXIS.min, iymin);
}
예제 #3
0
파일: interpol.c 프로젝트: ujaved/gnuplot
static void
do_cubic(
    struct curve_points *plot,	/* still containes old plot->points */
    spline_coeff *sc,		/* generated by cp_tridiag */
    int first_point,		/* where to start in plot->points */
    int num_points,		/* to determine end in plot->points */
    struct coordinate *dest)	/* where to put the interpolated data */
{
    double xdiff, temp, x, y;
    double xstart, xend;	/* Endpoints of the sampled x range */
    int i, l;
    struct coordinate GPHUGE *this_points;

    /* min and max in internal (eg logged) co-ordinates. We update
     * these, then update the external extrema in user co-ordinates
     * at the end.
     */
    double ixmin, ixmax, iymin, iymax;
    double sxmin, sxmax, symin, symax;	/* starting values of above */

    x_axis = plot->x_axis;
    y_axis = plot->y_axis;

    ixmin = sxmin = AXIS_LOG_VALUE(x_axis, X_AXIS.min);
    ixmax = sxmax = AXIS_LOG_VALUE(x_axis, X_AXIS.max);
    iymin = symin = AXIS_LOG_VALUE(y_axis, Y_AXIS.min);
    iymax = symax = AXIS_LOG_VALUE(y_axis, Y_AXIS.max);

    this_points = (plot->points) + first_point;

    l = 0;

    /* HBB 20010727: Sample only across the actual x range, not the
     * full range of input data */
#if SAMPLE_CSPLINES_TO_FULL_RANGE
    xstart = this_points[0].x;
    xend = this_points[num_points - 1].x;
#else
    xstart = GPMAX(this_points[0].x, sxmin);
    xend = GPMIN(this_points[num_points - 1].x, sxmax);

    if (xstart >= xend)
	int_error(plot->token,
		  "Cannot smooth: no data within fixed xrange!");
#endif
    xdiff = (xend - xstart) / (samples_1 - 1);

    for (i = 0; i < samples_1; i++) {
	x = xstart + i * xdiff;

	/* Move forward to the spline interval this point is in */
	while ((x >= this_points[l + 1].x) && (l < num_points - 2))
	    l++;

	/* KB 981107: With logarithmic x axis the values were
         * converted back to linear scale before calculating the
         * coefficients. Use exponential for log x values. */
	temp = AXIS_DE_LOG_VALUE(x_axis, x)
	    - AXIS_DE_LOG_VALUE(x_axis, this_points[l].x);

	/* Evaluate cubic spline polynomial */
	y = ((sc[l][3] * temp + sc[l][2]) * temp + sc[l][1]) * temp + sc[l][0];

	/* With logarithmic y axis, we need to convert from linear to
         * log scale now. */
	if (Y_AXIS.log) {
	    if (y > 0.)
		y = AXIS_DO_LOG(y_axis, y);
	    else
		y = symin - (symax - symin);
	}

	dest[i].type = INRANGE;
	STORE_AND_FIXUP_RANGE(dest[i].x, x, dest[i].type, ixmin, ixmax, X_AXIS.autoscale, NOOP, continue);
	STORE_AND_FIXUP_RANGE(dest[i].y, y, dest[i].type, iymin, iymax, Y_AXIS.autoscale, NOOP, NOOP);

	dest[i].xlow = dest[i].xhigh = dest[i].x;
	dest[i].ylow = dest[i].yhigh = dest[i].y;

	dest[i].z = -1;

    }

    UPDATE_RANGE(ixmax > sxmax, X_AXIS.max, ixmax, x_axis);
    UPDATE_RANGE(ixmin < sxmin, X_AXIS.min, ixmin, x_axis);
    UPDATE_RANGE(iymax > symax, Y_AXIS.max, iymax, y_axis);
    UPDATE_RANGE(iymin < symin, Y_AXIS.min, iymin, y_axis);

}
예제 #4
0
static void
do_cubic(
    struct curve_points *plot,	/* still containes old plot->points */
    spline_coeff *sc,		/* generated by cp_tridiag */
    int first_point,		/* where to start in plot->points */
    int num_points,		/* to determine end in plot->points */
    struct coordinate *dest)	/* where to put the interpolated data */
{
    double xdiff, temp, x, y;
    double xstart, xend;	/* Endpoints of the sampled x range */
    int i, l;
    struct coordinate GPHUGE *this_points;

    /* min and max in internal (eg logged) co-ordinates. We update
     * these, then update the external extrema in user co-ordinates
     * at the end.
     */
    double ixmin, ixmax, iymin, iymax;
    double sxmin, sxmax, symin, symax;	/* starting values of above */

    x_axis = plot->x_axis;
    y_axis = plot->y_axis;

    ixmin = sxmin = X_AXIS.min;
    ixmax = sxmax = X_AXIS.max;
    iymin = symin = Y_AXIS.min;
    iymax = symax = Y_AXIS.max;

    this_points = (plot->points) + first_point;

    l = 0;

    /* HBB 20010727: Sample only across the actual x range, not the
     * full range of input data */
#if SAMPLE_CSPLINES_TO_FULL_RANGE
    xstart = this_points[0].x;
    xend = this_points[num_points - 1].x;
#else
    xstart = GPMAX(this_points[0].x, sxmin);
    xend = GPMIN(this_points[num_points - 1].x, sxmax);

    if (xstart >= xend) {
	/* This entire segment lies outside the current x range. */
	for (i = 0; i < samples_1; i++)
	    dest[i].type = OUTRANGE;
	return;
    }
#endif
    xdiff = (xend - xstart) / (samples_1 - 1);

    for (i = 0; i < samples_1; i++) {
	x = xstart + i * xdiff;

	/* Move forward to the spline interval this point is in */
	while ((x >= this_points[l + 1].x) && (l < num_points - 2))
	    l++;

	temp = x - this_points[l].x;

	/* Evaluate cubic spline polynomial */
	y = ((sc[l][3] * temp + sc[l][2]) * temp + sc[l][1]) * temp + sc[l][0];

	/* With logarithmic y axis, we need to convert from linear to log scale now */
	if (Y_AXIS.log && y <= 0)
		y = symin - (symax - symin);

	dest[i].type = INRANGE;
	STORE_AND_FIXUP_RANGE(dest[i].x, x, dest[i].type, ixmin, ixmax, X_AXIS.autoscale);
	STORE_AND_FIXUP_RANGE(dest[i].y, y, dest[i].type, iymin, iymax, Y_AXIS.autoscale);

	dest[i].xlow = dest[i].xhigh = dest[i].x;
	dest[i].ylow = dest[i].yhigh = dest[i].y;

	dest[i].z = -1;

    }

    UPDATE_RANGE(ixmax > sxmax, X_AXIS.max, ixmax);
    UPDATE_RANGE(ixmin < sxmin, X_AXIS.min, ixmin);
    UPDATE_RANGE(iymax > symax, Y_AXIS.max, iymax);
    UPDATE_RANGE(iymin < symin, Y_AXIS.min, iymin);

}