expressions: Add support for mult and fuzzbits arguments to TRUNC function.

[pspp] / src / language / expressions / helpers.c

diff --git a/src/language/expressions/helpers.c b/src/language/expressions/helpers.c
index 57e17713b994f9036c97ddda0d829035fb726605..6e73887285a8d79543b21573ee84d7fc09c415ed 100644 (file)
--- a/src/language/expressions/helpers.c
+++ b/src/language/expressions/helpers.c
@@ -665,19 +665,29 @@ npdf_beta (double x, double a, double b, double lambda)
 }
 
 double
-round_nearest (double x, double mult, double fuzzbits)
+round__ (double x, double mult, double fuzzbits, double adjustment)
 {
-  double adjustment;
-
   if (fuzzbits <= 0)
     fuzzbits = settings_get_fuzzbits ();
-  adjustment = .5 + exp2 (fuzzbits - DBL_MANT_DIG);
+  adjustment += exp2 (fuzzbits - DBL_MANT_DIG);
 
   x /= mult;
   x = x >= 0. ? floor (x + adjustment) : -floor (-x + adjustment);
   return x * mult;
 }
 
+double
+round_nearest (double x, double mult, double fuzzbits)
+{
+  return round__ (x, mult, fuzzbits, .5);
+}
+
+double
+round_zero (double x, double mult, double fuzzbits)
+{
+  return round__ (x, mult, fuzzbits, 0);
+}
+
 struct substring
 replace_string (struct expression *e,
                 struct substring haystack,