-/* Write the legend of the chart */
-void
-histogram_write_legend(struct chart *ch, const struct normal_curve *norm)
-{
- char buf[100];
- pl_savestate_r(ch->lp);
-
- sprintf(buf,"N = %.2f",norm->N);
- pl_move_r(ch->lp, ch->legend_left, ch->data_bottom);
- pl_alabel_r(ch->lp,0,'b',buf);
-
- sprintf(buf,"Mean = %.1f",norm->mean);
- pl_fmove_r(ch->lp,ch->legend_left,ch->data_bottom + ch->font_size * 1.5);
- pl_alabel_r(ch->lp,0,'b',buf);
-
- sprintf(buf,"Std. Dev = %.2f",norm->stddev);
- pl_fmove_r(ch->lp,ch->legend_left,ch->data_bottom + ch->font_size * 1.5 * 2);
- pl_alabel_r(ch->lp,0,'b',buf);
-
- pl_restorestate_r(ch->lp);
-}
-
-static void hist_draw_bar(struct chart *ch, const gsl_histogram *hist, int bar);
-
-
-static void
-hist_draw_bar(struct chart *ch, const gsl_histogram *hist, int bar)
-{
- double upper;
- double lower;
- double height;
-
- const size_t bins = gsl_histogram_bins(hist);
- const double x_pos = (ch->data_right - ch->data_left) * bar / (double) bins ;
- const double width = (ch->data_right - ch->data_left) / (double) bins ;
-
-
- assert ( 0 == gsl_histogram_get_range(hist, bar, &lower, &upper));
-
- assert( upper >= lower);
-
- height = gsl_histogram_get(hist, bar) *
- (ch->data_top - ch->data_bottom) / gsl_histogram_max_val(hist);
-
- pl_savestate_r(ch->lp);
- pl_move_r(ch->lp,ch->data_left, ch->data_bottom);
- pl_fillcolorname_r(ch->lp, ch->fill_colour);
- pl_filltype_r(ch->lp,1);
-
-
- pl_fboxrel_r(ch->lp,
- x_pos, 0,
- x_pos + width, height);
-
- pl_restorestate_r(ch->lp);
-
- {
- char buf[5];
- snprintf(buf,5,"%g",(upper + lower) / 2.0);
- draw_tick(ch, TICK_ABSCISSA,
- x_pos + width / 2.0, buf);
- }
-
-}
-
-
-
-
-void
-histogram_plot(const gsl_histogram *hist,
- const char *factorname,
- const struct normal_curve *norm, short show_normal)
-{
- int i;
- int bins;
-
- struct chart ch;
-
- bins = gsl_histogram_bins(hist);
-
- chart_initialise(&ch);
- chart_write_title(&ch, _("HISTOGRAM"));
-
- chart_write_ylabel(&ch, _("Frequency"));
- chart_write_xlabel(&ch, factorname);
-
- chart_write_yscale(&ch, 0, gsl_histogram_max_val(hist), 5);
-
- for ( i = 0 ; i < bins ; ++i )
- hist_draw_bar(&ch, hist, i);
-
- histogram_write_legend(&ch, norm);
-
- if ( show_normal )
- {
- /* Draw the normal curve */
-
- double d ;
- double x_min, x_max, not_used ;
- double abscissa_scale ;
- double ordinate_scale ;
- double range ;
-
- gsl_histogram_get_range(hist, 0, &x_min, ¬_used);
- range = not_used - x_min;
- gsl_histogram_get_range(hist, bins - 1, ¬_used, &x_max);
- assert(range == x_max - not_used);
-
- abscissa_scale = (ch.data_right - ch.data_left) / (x_max - x_min);
- ordinate_scale = (ch.data_top - ch.data_bottom) /
- gsl_histogram_max_val(hist) ;
-
- pl_move_r(ch.lp, ch.data_left, ch.data_bottom);
- for( d = ch.data_left;
- d <= ch.data_right ;
- d += (ch.data_right - ch.data_left) / 100.0)
- {
- const double x = (d - ch.data_left) / abscissa_scale + x_min ;
- const double y = norm->N * range *
- gsl_ran_gaussian_pdf(x - norm->mean, norm->stddev);
-
- pl_fcont_r(ch.lp, d, ch.data_bottom + y * ordinate_scale);
-
- }
- pl_endpath_r(ch.lp);
-
- }
- chart_finalise(&ch);
-}
-