X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Foutput%2Fcharts%2Fplot-hist-cairo.c;h=d196b1572373ed71758f4d7edbda23b398caed56;hb=5865b44f23925431d48a9a732e389d1337a5b201;hp=87409b1a90937bd76a62c668e033df74bbc80aea;hpb=6b3938165488f5562ab4c1e4a808f2f36407956c;p=pspp
diff --git a/src/output/charts/plot-hist-cairo.c b/src/output/charts/plot-hist-cairo.c
index 87409b1a90..d196b15723 100644
--- a/src/output/charts/plot-hist-cairo.c
+++ b/src/output/charts/plot-hist-cairo.c
@@ -1,5 +1,5 @@
/* PSPP - a program for statistical analysis.
- Copyright (C) 2009, 2011 Free Software Foundation, Inc.
+ Copyright (C) 2009, 2011, 2014, 2015 Free Software Foundation, Inc.
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
@@ -15,15 +15,17 @@
along with this program. If not, see . */
#include
-
+#include "math/chart-geometry.h"
#include "output/charts/plot-hist.h"
+#include
#include
#include "data/val-type.h"
#include "output/cairo-chart.h"
#include "gl/xvasprintf.h"
+#include "gl/minmax.h"
#include "gettext.h"
#define _(msgid) gettext (msgid)
@@ -67,29 +69,24 @@ histogram_write_legend (cairo_t *cr, const struct xrchart_geometry *geom,
static void
hist_draw_bar (cairo_t *cr, const struct xrchart_geometry *geom,
- const gsl_histogram *h, int bar, bool label)
+ const gsl_histogram *h, int bar)
{
double upper;
double lower;
double height;
- const size_t bins = gsl_histogram_bins (h);
-
- const double x_pos =
- (geom->axis[SCALE_ABSCISSA].data_max - geom->axis[SCALE_ABSCISSA].data_min) *
- bar / (double) bins ;
-
- const double width =
- (geom->axis[SCALE_ABSCISSA].data_max - geom->axis[SCALE_ABSCISSA].data_min) / (double) bins ;
-
assert ( 0 == gsl_histogram_get_range (h, bar, &lower, &upper));
-
assert ( upper >= lower);
+ const double x_pos =
+ (lower - geom->axis[SCALE_ABSCISSA].min) * geom->axis[SCALE_ABSCISSA].scale
+ + geom->axis[SCALE_ABSCISSA].data_min;
+ const double width = (upper - lower) * geom->axis[SCALE_ABSCISSA].scale;
+
height = geom->axis[SCALE_ORDINATE].scale * gsl_histogram_get (h, bar);
cairo_rectangle (cr,
- geom->axis[SCALE_ABSCISSA].data_min + x_pos,
+ x_pos,
geom->axis[SCALE_ORDINATE].data_min,
width, height);
cairo_save (cr);
@@ -100,10 +97,6 @@ hist_draw_bar (cairo_t *cr, const struct xrchart_geometry *geom,
cairo_fill_preserve (cr);
cairo_restore (cr);
cairo_stroke (cr);
-
- if (label)
- draw_tick (cr, geom, SCALE_ABSCISSA,
- x_pos + width / 2.0, "%g", (upper + lower) / 2.0);
}
void
@@ -125,13 +118,17 @@ xrchart_draw_histogram (const struct chart_item *chart_item, cairo_t *cr,
return;
}
- bins = gsl_histogram_bins (h->gsl_hist);
+ xrchart_write_yscale (cr, geom, 0, gsl_histogram_max_val (h->gsl_hist));
+ xrchart_write_xscale (cr, geom, gsl_histogram_min (h->gsl_hist),
+ gsl_histogram_max (h->gsl_hist));
- xrchart_write_yscale (cr, geom, 0, gsl_histogram_max_val (h->gsl_hist), 5);
+
+ /* Draw the ticks and compute if the rendered tick text is wider than the bin */
+ bins = gsl_histogram_bins (h->gsl_hist);
for (i = 0; i < bins; i++)
{
- hist_draw_bar (cr, geom, h->gsl_hist, i, true);
+ hist_draw_bar (cr, geom, h->gsl_hist, i);
}
histogram_write_legend (cr, geom, h->n, h->mean, h->stddev);
@@ -140,32 +137,38 @@ xrchart_draw_histogram (const struct chart_item *chart_item, cairo_t *cr,
&& h->n != SYSMIS && h->mean != SYSMIS && h->stddev != SYSMIS)
{
/* Draw the normal curve */
- double d;
- double x_min, x_max, not_used;
- double abscissa_scale;
+ double x_min, x_max;
double ordinate_scale;
- double range;
+ double binwidth;
+ double x;
- gsl_histogram_get_range (h->gsl_hist, 0, &x_min, ¬_used);
- range = not_used - x_min;
- gsl_histogram_get_range (h->gsl_hist, bins - 1, ¬_used, &x_max);
+ gsl_histogram_get_range (h->gsl_hist, 0, &x_min, &x_max);
+ binwidth = x_max - x_min;
- abscissa_scale = (geom->axis[SCALE_ABSCISSA].data_max - geom->axis[SCALE_ABSCISSA].data_min) / (x_max - x_min);
- ordinate_scale = (geom->axis[SCALE_ORDINATE].data_max - geom->axis[SCALE_ORDINATE].data_min) /
- gsl_histogram_max_val (h->gsl_hist);
+ /* The integral over the histogram is binwidth * sum(bin_i), while the integral over the pdf is 1 */
+ /* Therefore the pdf has to be scaled accordingly such that the integrals are equal */
+ ordinate_scale = binwidth * gsl_histogram_sum(h->gsl_hist);
+
+ /* Clip normal curve to the rectangle formed by the axes. */
+ cairo_save (cr);
+ cairo_rectangle (cr, geom->axis[SCALE_ABSCISSA].data_min, geom->axis[SCALE_ORDINATE].data_min,
+ geom->axis[SCALE_ABSCISSA].data_max - geom->axis[SCALE_ABSCISSA].data_min,
+ geom->axis[SCALE_ORDINATE].data_max - geom->axis[SCALE_ORDINATE].data_min);
+ cairo_clip (cr);
cairo_move_to (cr, geom->axis[SCALE_ABSCISSA].data_min, geom->axis[SCALE_ORDINATE].data_min);
- for (d = geom->axis[SCALE_ABSCISSA].data_min;
- d <= geom->axis[SCALE_ABSCISSA].data_max;
- d += (geom->axis[SCALE_ABSCISSA].data_max - geom->axis[SCALE_ABSCISSA].data_min) / 100.0)
+ for (x = geom->axis[SCALE_ABSCISSA].min;
+ x <= geom->axis[SCALE_ABSCISSA].max;
+ x += (geom->axis[SCALE_ABSCISSA].max - geom->axis[SCALE_ABSCISSA].min) / 100.0)
{
- const double x = (d - geom->axis[SCALE_ABSCISSA].data_min) / abscissa_scale + x_min;
- const double y = h->n * range *
- gsl_ran_gaussian_pdf (x - h->mean, h->stddev);
-
- cairo_line_to (cr, d, geom->axis[SCALE_ORDINATE].data_min + y * ordinate_scale);
-
+ const double y = gsl_ran_gaussian_pdf (x - h->mean, h->stddev) * ordinate_scale;
+ /* Transform to drawing coordinates */
+ const double x_pos = (x - geom->axis[SCALE_ABSCISSA].min) * geom->axis[SCALE_ABSCISSA].scale + geom->axis[SCALE_ABSCISSA].data_min;
+ const double y_pos = (y - geom->axis[SCALE_ORDINATE].min) * geom->axis[SCALE_ORDINATE].scale + geom->axis[SCALE_ORDINATE].data_min;
+ cairo_line_to (cr, x_pos, y_pos);
}
cairo_stroke (cr);
+
+ cairo_restore (cr);
}
}