1 /* PSPP - a program for statistical analysis.
2 Copyright (C) 2014, 2015 Free Software Foundation, Inc.
4 This program is free software: you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation, either version 3 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program. If not, see <http://www.gnu.org/licenses/>. */
19 #include "output/charts/scatterplot.h"
21 #include "data/case.h"
22 #include "data/casereader.h"
23 #include "data/variable.h"
24 #include "output/cairo-chart.h"
25 #include "libpspp/str.h"
26 #include "libpspp/message.h"
29 #define _(msgid) gettext (msgid)
33 xrchart_draw_scatterplot (const struct chart_item *chart_item, cairo_t *cr,
34 struct xrchart_geometry *geom)
36 const struct scatterplot_chart *spc = to_scatterplot_chart (chart_item);
37 struct casereader *data;
39 /* While reading the cases, a list with categories of the byvar is build */
40 /* All distinct values are stored in catvals */
41 /* Each category will later have a different plot colour */
42 const int MAX_PLOT_CATS = 20;
43 union value catvals[MAX_PLOT_CATS];
47 const struct xrchart_colour *colour;
50 byvar_width = var_get_width (spc->byvar);
52 xrchart_write_xscale (cr, geom, spc->x_min, spc->x_max);
53 xrchart_write_yscale (cr, geom, spc->y_min, spc->y_max);
54 xrchart_write_title (cr, geom, _("Scatterplot %s"), chart_item->title);
55 xrchart_write_xlabel (cr, geom, spc->xlabel);
56 xrchart_write_ylabel (cr, geom, spc->ylabel);
59 data = casereader_clone (spc->data);
60 for (; (c = casereader_read (data)) != NULL; case_unref (c))
64 const union value *val = case_data_idx (c,SP_IDX_BY);
65 for(i=0;i<n_catvals && !value_equal (&catvals[i],val,byvar_width);i++);
66 if (i == n_catvals) /* No entry found */
68 if (n_catvals < MAX_PLOT_CATS)
71 ds_init_empty (&label);
72 if (var_is_value_missing (spc->byvar,val,MV_ANY))
73 ds_put_cstr (&label,"missing");
75 var_append_value_name (spc->byvar,val,&label);
76 value_clone (&catvals[n_catvals++],val,byvar_width);
78 geom->dataset = xrealloc (geom->dataset,
79 geom->n_datasets * sizeof (*geom->dataset));
81 geom->dataset[geom->n_datasets - 1] = strdup (ds_cstr(&label));
84 else /* Use the last plot category */
86 *(spc->byvar_overflow) = true;
91 colour = &data_colour[i % XRCHART_N_COLOURS];
92 cairo_set_source_rgb (cr,
94 colour->green / 255.0,
95 colour->blue / 255.0);
97 xrchart_datum (cr, geom, 0,
98 case_data_idx (c, SP_IDX_X)->f,
99 case_data_idx (c, SP_IDX_Y)->f);
101 casereader_destroy (data);
104 for(i=0;i<n_catvals;i++)
105 value_destroy (&catvals[i],byvar_width);
108 xrchart_write_legend (cr, geom);