X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fmath%2Fchart-geometry.c;h=eb0ad9282a854885768472319a899dbfba6c14ea;hb=391b4634b4b46764360c4c39ce94bb90d6e3176a;hp=736f89934b986648cc6ca1c423473a520d7676a5;hpb=43b1296aafe7582e7dbe6c2b6a8b478d7d9b0fcf;p=pspp

diff --git a/src/math/chart-geometry.c b/src/math/chart-geometry.c
index 736f89934b..eb0ad9282a 100644
--- a/src/math/chart-geometry.c
+++ b/src/math/chart-geometry.c
@@ -20,24 +20,30 @@
 
 #include "chart-geometry.h"
 
+static const double standard_ticks[] = {1, 2, 5, 10};
+
+
 /* Adjust tick to be a sensible value
    ie:  ... 0.1,0.2,0.5,   1,2,5,  10,20,50 ... */
 double
-chart_rounded_tick(double tick)
+chart_rounded_tick (double tick)
 {
-
   int i;
 
   double diff = DBL_MAX;
   double t = tick;
 
-  static const double standard_ticks[] = {1, 2, 5, 10};
+  double factor;
 
-  const double factor = pow(10,ceil(log10(standard_ticks[0] / tick))) ;
+  /* Avoid arithmetic problems with very small values */
+  if (fabs (tick) < DBL_EPSILON)
+     return 0;
+
+  factor = pow (10,ceil (log10 (standard_ticks[0] / tick)));
 
   for (i = 3  ; i >= 0 ; --i)
     {
-      const double d = fabs( tick - standard_ticks[i] / factor ) ;
+      const double d = fabs (tick - standard_ticks[i] / factor);
 
       if ( d < diff )
 	{
@@ -47,6 +53,5 @@ chart_rounded_tick(double tick)
     }
 
   return t;
-
 }