X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=src%2FTests%2FFace.hs;h=8c28a0553fd7dc6b095a5d7fa9c4c48884a2d752;hb=9b49c83260ab5a3d94fc12fcefa7edcaabbd28f4;hp=f9de1e7c6f6e8dde049693d08f5d264148d1662c;hpb=25c8b387c4b655751265605bd4af033698624f38;p=spline3.git

diff --git a/src/Tests/Face.hs b/src/Tests/Face.hs
index f9de1e7..8c28a05 100644
--- a/src/Tests/Face.hs
+++ b/src/Tests/Face.hs
@@ -1,10 +1,12 @@
 module Tests.Face
 where
 
+import Control.Monad (unless)
+import Test.HUnit
 import Test.QuickCheck
 
 import Comparisons
-import Cube (Cube(grid), top)
+import Cube (Cube(grid), cube_at, top)
 import Face (face0,
              face2,
              face5,
@@ -13,9 +15,103 @@ import Face (face0,
              tetrahedron2,
              tetrahedron3,
              tetrahedrons)
-import Grid (Grid(h))
+import Grid (Grid(h), make_grid)
 import Tetrahedron
 
+
+-- HUnit tests.
+
+-- | An HUnit assertion that wraps the almost_equals function. Stolen
+--   from the definition of assertEqual in Test/HUnit/Base.hs.
+assertAlmostEqual :: String -> Double -> Double -> Assertion
+assertAlmostEqual preface expected actual =
+  unless (actual ~= expected) (assertFailure msg)
+ where msg = (if null preface then "" else preface ++ "\n") ++
+             "expected: " ++ show expected ++ "\n but got: " ++ show actual
+
+
+-- | Values of the function f(x,y,z) = 1 + x + xy + xyz taken at nine
+--   points (hi, hj, jk) with h = 1. From example one in the paper.
+--   Used in the next bunch of tests.
+trilinear :: [[[Double]]]
+trilinear = [ [ [ 1, 2, 3 ],
+                [ 1, 3, 5 ],
+                [ 1, 4, 7 ] ],
+              [ [ 1, 2, 3 ],
+                [ 1, 4, 7 ],
+                [ 1, 6, 11 ] ],
+              [ [ 1, 2, 3 ],
+                [ 1, 5, 9 ],
+                [ 1, 8, 15 ]]]
+
+-- | Check the value of c0030 for any tetrahedron belonging to the
+--   cube centered on (1,1,1) with a grid constructed from the
+--   trilinear values. See example one in the paper.
+test_trilinear_c0030 :: Test
+test_trilinear_c0030 =
+    TestCase $ assertAlmostEqual "c0030 is correct" (c t 0 0 3 0) (17/8)
+      where
+        g = make_grid 1 trilinear
+        cube = cube_at g 1 1 1
+        t = head (tetrahedrons cube) -- Any one will do.
+
+
+-- | Check the value of c0003 for any tetrahedron belonging to the
+--   cube centered on (1,1,1) with a grid constructed from the
+--   trilinear values. See example one in the paper.
+test_trilinear_c0003 :: Test
+test_trilinear_c0003 =
+    TestCase $ assertAlmostEqual "c0003 is correct" (c t 0 0 0 3) (27/8)
+      where
+        g = make_grid 1 trilinear
+        cube = cube_at g 1 1 1
+        t = head (tetrahedrons cube) -- Any one will do.
+
+
+-- | Check the value of c0021 for any tetrahedron belonging to the
+--   cube centered on (1,1,1) with a grid constructed from the
+--   trilinear values. See example one in the paper.
+test_trilinear_c0021 :: Test
+test_trilinear_c0021 =
+    TestCase $ assertAlmostEqual "c0021 is correct" (c t 0 0 2 1) (61/24)
+      where
+        g = make_grid 1 trilinear
+        cube = cube_at g 1 1 1
+        t = head (tetrahedrons cube) -- Any one will do.
+
+
+-- | Check the value of c0012 for any tetrahedron belonging to the
+--   cube centered on (1,1,1) with a grid constructed from the
+--   trilinear values. See example one in the paper.
+test_trilinear_c0012 :: Test
+test_trilinear_c0012 =
+    TestCase $ assertAlmostEqual "c0012 is correct" (c t 0 0 1 2) (71/24)
+      where
+        g = make_grid 1 trilinear
+        cube = cube_at g 1 1 1
+        t = head (tetrahedrons cube) -- Any one will do.
+
+
+-- | Check the value of c0120 for any tetrahedron belonging to the
+--   cube centered on (1,1,1) with a grid constructed from the
+--   trilinear values. See example one in the paper.
+test_trilinear_c0120 :: Test
+test_trilinear_c0120 =
+    TestCase $ assertAlmostEqual "c0120 is correct" (c t 0 1 2 0) (55/24)
+      where
+        g = make_grid 1 trilinear
+        cube = cube_at g 1 1 1
+        t = head (tetrahedrons cube) -- Any one will do.
+
+
+face_tests :: [Test]
+face_tests = [test_trilinear_c0030,
+              test_trilinear_c0003,
+              test_trilinear_c0021,
+              test_trilinear_c0012,
+              test_trilinear_c0120]
+
+
 -- QuickCheck Tests.
 
 -- | Since the grid size is necessarily positive, all tetrahedrons
@@ -31,6 +127,22 @@ prop_all_volumes_positive c =
       nonpositive_volumes = filter (<= 0) volumes
 
 
+-- | Given in Sorokina and Zeilfelder, p. 78.
+prop_cijk1_identity :: Cube -> Bool
+prop_cijk1_identity cube =
+     and [ c t0' i j k 1 ~= (c t1' (i+1) j k 0) * ((b0 t0') (v3 t1')) +
+                            (c t1' i (j+1) k 0) * ((b1 t0') (v3 t1')) +
+                            (c t1' i j (k+1) 0) * ((b2 t0') (v3 t1')) +
+                            (c t1' i j k 1) * ((b3 t0') (v3 t1')) | i <- [0..2],
+                                                                    j <- [0..2],
+                                                                    k <- [0..2],
+                                                                    i + j + k == 2]
+      where
+        t0 = tetrahedron0 (face0 cube)
+        t1 = tetrahedron1 (face0 cube)
+        t0' = Tetrahedron cube (v3 t0) (v2 t0) (v1 t0) (v0 t0)
+        t1' = Tetrahedron cube (v3 t1) (v2 t1) (v0 t1) (v1 t1)
+
 -- | Given in Sorokina and Zeilfelder, p. 79.
 prop_c0120_identity1 :: Cube -> Bool
 prop_c0120_identity1 cube =