}
}
-double
-round_nearest (double x, double mult, double fuzzbits)
+static double
+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,
return result;
}
+
+static int
+compare_doubles (const void *a_, const void *b_)
+{
+ const double *ap = a_;
+ const double *bp = b_;
+ double a = *ap;
+ double b = *bp;
+
+ /* Sort SYSMIS to the end. */
+ return (a == b ? 0
+ : a == SYSMIS ? 1
+ : b == SYSMIS ? -1
+ : a > b ? 1 : -1);
+}
+
+double
+median (double *a, size_t n)
+{
+ /* Sort the array in-place, sorting SYSMIS to the end. */
+ qsort (a, n, sizeof *a, compare_doubles);
+
+ /* Drop SYSMIS. */
+ n = count_valid (a, n);
+
+ return (!n ? SYSMIS
+ : n % 2 ? a[n / 2]
+ : (a[n / 2 - 1] + a[n / 2]) / 2.0);
+}