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);
}
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);
}
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);
}
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);
}