X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=src%2FCube.hs;h=6e67d4cd4d6d3c7311a7c095e4b43be9387ba69b;hb=fa764bc6679c8fe62341918c271df287365eaa04;hp=83f4da38f52638f300a655ce88dbfc3d46a9cd8a;hpb=1b041ed87130177797758f471aa78fe55e65c9ae;p=spline3.git

diff --git a/src/Cube.hs b/src/Cube.hs
index 83f4da3..6e67d4c 100644
--- a/src/Cube.hs
+++ b/src/Cube.hs
@@ -64,8 +64,7 @@ instance Show Cube where
         " ymin: " ++ (show (ymin cube)) ++ "\n" ++
         " ymax: " ++ (show (ymax cube)) ++ "\n" ++
         " zmin: " ++ (show (zmin cube)) ++ "\n" ++
-        " zmax: " ++ (show (zmax cube)) ++ "\n" ++
-        " fv: " ++ (show (Cube.fv cube)) ++ "\n"
+        " zmax: " ++ (show (zmax cube)) ++ "\n"
         where
           subscript =
               (show (i cube)) ++ "," ++ (show (j cube)) ++ "," ++ (show (k cube))
@@ -74,7 +73,7 @@ instance Show Cube where
 -- | The left-side boundary of the cube. See Sorokina and Zeilfelder,
 --   p. 76.
 xmin :: Cube -> Double
-xmin cube = (2*i' - 1)*delta / 2
+xmin cube = (i' - 1/2)*delta
     where
       i' = fromIntegral (i cube) :: Double
       delta = h cube
@@ -82,7 +81,7 @@ xmin cube = (2*i' - 1)*delta / 2
 -- | The right-side boundary of the cube. See Sorokina and Zeilfelder,
 --   p. 76.
 xmax :: Cube -> Double
-xmax cube = (2*i' + 1)*delta / 2
+xmax cube = (i' + 1/2)*delta
     where
       i' = fromIntegral (i cube) :: Double
       delta = h cube
@@ -90,7 +89,7 @@ xmax cube = (2*i' + 1)*delta / 2
 -- | The front boundary of the cube. See Sorokina and Zeilfelder,
 --   p. 76.
 ymin :: Cube -> Double
-ymin cube = (2*j' - 1)*delta / 2
+ymin cube = (j' - 1/2)*delta
     where
       j' = fromIntegral (j cube) :: Double
       delta = h cube
@@ -98,7 +97,7 @@ ymin cube = (2*j' - 1)*delta / 2
 -- | The back boundary of the cube. See Sorokina and Zeilfelder,
 --   p. 76.
 ymax :: Cube -> Double
-ymax cube = (2*j' + 1)*delta / 2
+ymax cube = (j' + 1/2)*delta
     where
       j' = fromIntegral (j cube) :: Double
       delta = h cube
@@ -106,7 +105,7 @@ ymax cube = (2*j' + 1)*delta / 2
 -- | The bottom boundary of the cube. See Sorokina and Zeilfelder,
 --   p. 76.
 zmin :: Cube -> Double
-zmin cube = (2*k' - 1)*delta / 2
+zmin cube = (k' - 1/2)*delta
     where
       k' = fromIntegral (k cube) :: Double
       delta = h cube
@@ -114,7 +113,7 @@ zmin cube = (2*k' - 1)*delta / 2
 -- | The top boundary of the cube. See Sorokina and Zeilfelder,
 --   p. 76.
 zmax :: Cube -> Double
-zmax cube = (2*k' + 1)*delta / 2
+zmax cube = (k' + 1/2)*delta
     where
       k' = fromIntegral (k cube) :: Double
       delta = h cube
@@ -665,15 +664,15 @@ prop_opposite_octant_tetrahedra_disjoint6 cube =
 
 
 -- | Since the grid size is necessarily positive, all tetrahedra
---   (which comprise cubes of positive volume) must have positive volume
---   as well.
+--   (which comprise cubes of positive volume) must have positive
+--   volume as well.
 prop_all_volumes_positive :: Cube -> Bool
 prop_all_volumes_positive cube =
-    null nonpositive_volumes
+    all (>= 0) volumes
     where
       ts = tetrahedra cube
       volumes = map volume ts
-      nonpositive_volumes = filter (<= 0) volumes
+
 
 -- | In fact, since all of the tetrahedra are identical, we should
 --   already know their volumes. There's 24 tetrahedra to a cube, so