X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Foutput%2Fcharts%2Fspreadlevel-plot.c;h=5fd189d6e06c2f2fc8fb3cd75959f7fd857ce246;hb=507ebaea36737618ef8265a60cd3e9005d9f3457;hp=d5b6e3d01a33aa483f6968fd9493a9fffca30a2a;hpb=64ad089c50c954e9130448f1becfab0f6aff6a9b;p=pspp

diff --git a/src/output/charts/spreadlevel-plot.c b/src/output/charts/spreadlevel-plot.c
index d5b6e3d01a..5fd189d6e0 100644
--- a/src/output/charts/spreadlevel-plot.c
+++ b/src/output/charts/spreadlevel-plot.c
@@ -1,5 +1,5 @@
 /* PSPP - a program for statistical analysis.
-   Copyright (C) 2012 Free Software Foundation, Inc.
+   Copyright (C) 2012, 2020 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
@@ -19,7 +19,7 @@
 #include "output/charts/spreadlevel-plot.h"
 
 #include "libpspp/cast.h"
-#include "output/chart-item-provider.h"
+#include "output/chart-provider.h"
 
 #include "gl/xalloc.h"
 #include "gl/minmax.h"
@@ -28,11 +28,11 @@
 #include <float.h>
 #include <stdlib.h>
 
-struct chart_item *
+struct chart *
 spreadlevel_plot_create (const char *label, double tx_pwr)
 {
   struct spreadlevel_plot_chart *sl = xzalloc (sizeof *sl);
-  chart_item_init (&sl->chart_item, &spreadlevel_plot_chart_class, label);
+  chart_init (&sl->chart, &spreadlevel_plot_chart_class, label);
 
   sl->x_lower = DBL_MAX;
   sl->x_upper = -DBL_MAX;
@@ -44,19 +44,20 @@ spreadlevel_plot_create (const char *label, double tx_pwr)
 
   sl->n_data = 0;
   sl->data = NULL;
-  
-  return &sl->chart_item;
+
+  return &sl->chart;
 }
 
-void 
-spreadlevel_plot_add (struct chart_item *ci, double spread, double level)
+void
+spreadlevel_plot_add (struct chart *ci, double spread, double level)
 {
   struct spreadlevel_plot_chart *sl = to_spreadlevel_plot_chart (ci);
 
-  if ( sl->tx_pwr == 0)
+  /* Zero has a special meaning, in this implementation.  */
+  if (sl->tx_pwr == 0)
     {
-      spread = log (spread);
-      level = log (level);
+      spread = log (fabs (spread));
+      level = log (fabs (level));
     }
   else
     {
@@ -78,15 +79,15 @@ spreadlevel_plot_add (struct chart_item *ci, double spread, double level)
 
 
 static void
-spreadlevel_plot_chart_destroy (struct chart_item *chart_item)
+spreadlevel_plot_chart_destroy (struct chart *chart)
 {
-  struct spreadlevel_plot_chart *sl = to_spreadlevel_plot_chart (chart_item);
+  struct spreadlevel_plot_chart *sl = to_spreadlevel_plot_chart (chart);
 
   free (sl->data);
   free (sl);
 }
 
-const struct chart_item_class spreadlevel_plot_chart_class =
+const struct chart_class spreadlevel_plot_chart_class =
   {
     spreadlevel_plot_chart_destroy
   };