Merge pull request #58 from mgsloan/diameter_benchmark

More involved diameter benchmark + better implementation

test/diamBench.hs

@@ -1,22 +1,63 @@
-{-# LANGUAGE FlexibleInstances, TypeSynonymInstances, TypeFamilies, NoMonomorphismRestriction #-}
+{-# LANGUAGE FlexibleContexts #-}
+module DiamBench where
 import Criterion.Main
 import Diagrams.Prelude
+import Diagrams.ThreeD.Shapes
+import Diagrams.ThreeD.Types
 
 -- Comparing the performance of two different diameter implementations
 
--- Current definition:
+-- Old definition:
 diameter1 :: Enveloped a => V a -> a -> Scalar (V a)
 diameter1 v a = magnitude (envelopeV v a ^-^ envelopeV (negateV v) a)
 
--- Possibly faster definition (not according to these tests):
+-- New definition:
 diameter2 :: Enveloped a => V a -> a -> Scalar (V a)
-diameter2 v = maybe 0 (\env -> env u + env (negateV u)) . appEnvelope . getEnvelope
- where
-  u = normalized v
+diameter2 v a = case appEnvelope $ getEnvelope a of
+  (Just env) -> (env v + env (negateV v)) * magnitude v
+  Nothing -> 0
 
-test f = [ f (rotate (Deg d) unitX) | d <- [0.0, 5.0 .. 360.0] ]
+--test :: (VectorSpace v, Fractional (Scalar v), Enum (Scalar v)) => (v -> t) -> v -> [t]
+test f v = [ f (v ^* d) | d <- [0.0, 5.0 .. 100.0] ]
 
 main = defaultMain
-   [ bench "diameter1" $ nf (\d -> test (`diameter1` d)) (unitSquare :: D R2)
-   , bench "diameter2" $ nf (\d -> test (`diameter2` d)) (unitSquare :: D R2)
+   [ bench "diameter1" $ nf (\d -> test (`diameter1` d) $ 1 & 3) (unitSquare :: D R2)
+   , bench "diameter2" $ nf (\d -> test (`diameter2` d) $ 1 & 3) (unitSquare :: D R2)
+   , bench "diameter3" $ nf (\d -> test (`diameter1` d) $ (-1) & 1 & 3) (sphere :: D R3)
+   , bench "diameter4" $ nf (\d -> test (`diameter2` d) $ (-1) & 1 & 3) (sphere :: D R3)
    ]
+
+
+{- mgsloan's results
+
+warming up
+estimating clock resolution...
+mean is 1.277677 us (640001 iterations)
+found 3123 outliers among 639999 samples (0.5%)
+  2933 (0.5%) high severe
+estimating cost of a clock call...
+mean is 28.94072 ns (7 iterations)
+found 1 outliers among 7 samples (14.3%)
+  1 (14.3%) high severe
+
+benchmarking diameter1
+mean: 41.10492 us, lb 41.02676 us, ub 41.20513 us, ci 0.950
+std dev: 453.7027 ns, lb 370.9014 ns, ub 583.8290 ns, ci 0.950
+
+benchmarking diameter2
+mean: 40.12666 us, lb 40.04038 us, ub 40.23655 us, ci 0.950
+std dev: 498.8693 ns, lb 415.3504 ns, ub 637.7434 ns, ci 0.950
+
+benchmarking diameter3
+mean: 1.762319 us, lb 1.759122 us, ub 1.765858 us, ci 0.950
+std dev: 17.29888 ns, lb 15.30558 ns, ub 20.23129 ns, ci 0.950
+
+benchmarking diameter4
+mean: 1.692065 us, lb 1.687748 us, ub 1.698442 us, ci 0.950
+std dev: 26.41623 ns, lb 20.34119 ns, ub 40.98644 ns, ci 0.950
+found 4 outliers among 100 samples (4.0%)
+  3 (3.0%) high mild
+  1 (1.0%) high severe
+variance introduced by outliers: 8.481%
+variance is slightly inflated by outliers
+-}