1 /* PSPP - computes sample statistics.
2 Copyright (C) 2004 Free Software Foundation, Inc.
3 Written by John Darrington <john@darrington.wattle.id.au>
5 This program is free software; you can redistribute it and/or
6 modify it under the terms of the GNU General Public License as
7 published by the Free Software Foundation; either version 2 of the
8 License, or (at your option) any later version.
10 This program is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
25 #include "factor_stats.h"
28 /* Draw a box-and-whiskers plot
31 /* Draw an outlier on the plot CH
33 * The outlier is in (*wvp)[idx]
34 * If EXTREME is non zero, then consider it to be an extreme
38 draw_outlier(struct chart *ch, double centreline,
39 struct weighted_value **wvp,
45 draw_outlier(struct chart *ch, double centreline,
46 struct weighted_value **wvp,
53 #define MARKER_CIRCLE 4
59 (wvp[idx]->v.f - ch->y_min ) * ch->ordinate_scale,
60 extreme?MARKER_STAR:MARKER_CIRCLE,
63 pl_moverel_r(ch->lp, 10,0);
65 snprintf(label, 10, "%d", wvp[idx]->case_nos->num);
67 pl_alabel_r(ch->lp, 'l', 'c', label);
73 boxplot_draw_boxplot(struct chart *ch,
78 const double hinge[3],
79 struct weighted_value **wvp,
88 const double *hinge = m->hinge;
89 struct weighted_value **wvp = m->wvp;
90 const int n_data = m->n_data;
92 const double step = (hinge[2] - hinge[0]) * 1.5;
95 const double box_left = box_centre - box_width / 2.0;
97 const double box_right = box_centre + box_width / 2.0;
100 const double box_bottom =
101 ch->data_bottom + ( hinge[0] - ch->y_min ) * ch->ordinate_scale;
104 const double box_top =
105 ch->data_bottom + ( hinge[2] - ch->y_min ) * ch->ordinate_scale;
107 whisker[1] = hinge[2];
108 whisker[0] = wvp[0]->v.f;
110 for ( i = 0 ; i < n_data ; ++i )
112 if ( hinge[2] + step > wvp[i]->v.f)
113 whisker[1] = wvp[i]->v.f;
115 if ( hinge[0] - step > wvp[i]->v.f)
116 whisker[0] = wvp[i]->v.f;
121 const double bottom_whisker =
122 ch->data_bottom + ( whisker[0] - ch->y_min ) * ch->ordinate_scale;
124 const double top_whisker =
125 ch->data_bottom + ( whisker[1] - ch->y_min ) * ch->ordinate_scale;
128 pl_savestate_r(ch->lp);
132 pl_savestate_r(ch->lp);
133 pl_fillcolorname_r(ch->lp,ch->fill_colour);
134 pl_filltype_r(ch->lp,1);
141 pl_restorestate_r(ch->lp);
145 /* Draw the median */
146 pl_savestate_r(ch->lp);
147 pl_linewidth_r(ch->lp,5);
150 ch->data_bottom + ( hinge[1] - ch->y_min ) * ch->ordinate_scale,
152 ch->data_bottom + ( hinge[1] - ch->y_min ) * ch->ordinate_scale);
153 pl_restorestate_r(ch->lp);
156 /* Draw the bottom whisker */
163 /* Draw top whisker */
175 box_centre, bottom_whisker,
176 box_centre, box_bottom);
180 box_centre, top_whisker,
181 box_centre, box_top);
184 for ( i = 0 ; i < n_data ; ++i )
186 if ( wvp[i]->v.f >= hinge[2] + step )
187 draw_outlier(ch, box_centre, wvp, i,
188 ( wvp[i]->v.f > hinge[2] + 2 * step )
191 if ( wvp[i]->v.f <= hinge[0] - step )
192 draw_outlier(ch, box_centre, wvp, i,
193 ( wvp[i]->v.f < hinge[0] - 2 * step )
198 /* Draw tick mark on x axis */
199 draw_tick(ch, TICK_ABSCISSA, box_centre - ch->data_left, name);
201 pl_restorestate_r(ch->lp);
208 boxplot_draw_yscale(struct chart *ch , double y_max, double y_min)
216 y_tick = chart_rounded_tick(fabs(ch->y_max - ch->y_min) / 5.0);
218 ch->y_min = (ceil( ch->y_min / y_tick ) - 1.0 ) * y_tick;
220 ch->y_max = ( floor( ch->y_max / y_tick ) + 1.0 ) * y_tick;
222 ch->ordinate_scale = fabs(ch->data_top - ch->data_bottom)
223 / fabs(ch->y_max - ch->y_min) ;
226 /* Move to data bottom-left */
228 ch->data_left, ch->data_bottom);
230 for ( d = ch->y_min; d <= ch->y_max ; d += y_tick )
232 draw_tick (ch, TICK_ORDINATE, (d - ch->y_min ) * ch->ordinate_scale, "%g", d);