From: Michael Orlitzky <michael@orlitzky.com>
Date: Sun, 28 Aug 2011 01:13:03 +0000 (-0400)
Subject: Add the theta tolerance and nearly_equals, nearly_ge comparisons.
X-Git-Tag: 0.0.1~211
X-Git-Url: http://gitweb.michael.orlitzky.com/?p=spline3.git;a=commitdiff_plain;h=d1ee387490ef0ada8781f4bf81f82cce7f0006ba

Add the theta tolerance and nearly_equals, nearly_ge comparisons.
---

diff --git a/src/Comparisons.hs b/src/Comparisons.hs
index 6d8dc70..4a81444 100644
--- a/src/Comparisons.hs
+++ b/src/Comparisons.hs
@@ -8,6 +8,17 @@ where
 epsilon :: Double
 epsilon = 0.0001
 
+-- | A tiny margin of error.
+theta :: Double
+theta = 0.00000000000001
+
+-- | x almost equals y if x is within 'theta' of y.
+nearly_equals :: Double -> Double -> Bool
+nearly_equals x y = (abs (x - y)) < theta
+
+-- | Nearly greater-than or equal-to.
+nearly_ge :: Double -> Double -> Bool
+x `nearly_ge` y = (x > y) || (x `nearly_equals` y)
 
 -- | x almost equals y if x is within 'epsilon' of y.
 almost_equals :: Double -> Double -> Bool