diff options
-rw-r--r-- | rational.c | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/rational.c b/rational.c index cb555426ec..9601ee76df 100644 --- a/rational.c +++ b/rational.c @@ -1510,11 +1510,12 @@ nurat_truncate_n(int argc, VALUE *argv, VALUE self) /* * call-seq: - * rat.round -> integer - * rat.round(precision=0) -> integer or rational + * rat.round([ndigits] [, half: symbol]) -> integer or rational * - * Returns the truncated value (toward the nearest integer; - * 0.5 => 1; -0.5 => -1). + * Rounds +rat+ to a given precision in decimal digits (default 0 digits). + * + * Precision may be negative. Returns a rational when +ndigits+ + * is more than zero. * * Rational(3).round #=> 3 * Rational(2, 3).round #=> 1 @@ -1526,6 +1527,15 @@ nurat_truncate_n(int argc, VALUE *argv, VALUE self) * * Rational('-123.456').round(+1).to_f #=> -123.5 * Rational('-123.456').round(-1) #=> -120 + * + * The <code>half:</code> optional keyword same as Float#round is available. + * + * Rational(25, 100).round(1, half: :up) #=> (3/10) + * Rational(25, 100).round(1, half: :even) #=> (1/5) + * Rational(25, 100).round(1, half: :down) #=> (1/5) + * Rational(35, 100).round(1, half: :up) #=> (2/5) + * Rational(35, 100).round(1, half: :even) #=> (2/5) + * Rational(35, 100).round(1, half: :down) #=> (3/10) */ static VALUE nurat_round_n(int argc, VALUE *argv, VALUE self) |