diff options
Diffstat (limited to 'ext/bigdecimal/lib/bigdecimal/math.rb')
| -rw-r--r-- | ext/bigdecimal/lib/bigdecimal/math.rb | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/ext/bigdecimal/lib/bigdecimal/math.rb b/ext/bigdecimal/lib/bigdecimal/math.rb index dbc058b0b3..d1e8dbe326 100644 --- a/ext/bigdecimal/lib/bigdecimal/math.rb +++ b/ext/bigdecimal/lib/bigdecimal/math.rb @@ -125,11 +125,14 @@ module BigMath if neg = x < 0 x = -x end - if x == 1 + if x.round(prec) == 1 return pi / (neg ? -4 : 4) elsif inv = x > 1 x = 1 / x end + if dbl = x > 0.5 + x = (-1 + sqrt(1 + x**2, prec))/x + end n = prec + BigDecimal.double_fig y = x d = y @@ -143,6 +146,7 @@ module BigMath y += d r += 2 end + y *= 2 if dbl y = pi / 2 - y if inv y = -y if neg y |