+{-# LANGUAGE BangPatterns #-}
-- | The Grid module just contains the Grid type and two constructors
-- for it. We hide the main Grid constructor because we don't want
-- to allow instantiation of a grid with h <= 0.
Positive(..),
Property,
choose)
-import Assertions (assertAlmostEqual, assertClose, assertTrue)
+import Assertions (assertAlmostEqual, assertTrue)
import Comparisons ((~=))
import Cube (Cube(Cube),
find_containing_tetrahedron,
tetrahedron)
import Examples (trilinear, trilinear9x9x9, zeros, naturals_1d)
import FunctionValues (make_values, value_at)
-import Point (Point)
+import Point (Point(..))
import ScaleFactor (ScaleFactor)
import Tetrahedron (Tetrahedron, c, polynomial, v0, v1, v2, v3)
import ThreeDimensional (ThreeDimensional(..))
-- another in each direction (x,y,z).
data Grid = Grid { h :: Double, -- MUST BE GREATER THAN ZERO!
function_values :: Values3D }
- deriving (Eq, Show)
+ deriving (Show)
instance Arbitrary Grid where
return (make_grid h' fvs)
--- | The constructor that we want people to use. If we're passed a
--- non-positive grid size, we throw an error.
+-- | The constructor that we want people to use.
+-- Ignore non-positive grid sizes for performance.
make_grid :: Double -> Values3D -> Grid
-make_grid grid_size values
- | grid_size <= 0 = error "grid size must be positive"
- | otherwise = Grid grid_size values
+make_grid grid_size values =
+ Grid grid_size values
-- | Takes a grid and a position as an argument and returns the cube
--- centered on that position. If there is no cube there (i.e. the
--- position is outside of the grid), it will throw an error.
+-- centered on that position. If there is no cube there, well, you
+-- shouldn't have done that. The omitted "otherwise" case actually
+-- does improve performance.
cube_at :: Grid -> Int -> Int -> Int -> Cube
-cube_at g i j k
- | i < 0 = error "i < 0 in cube_at"
- | i >= xsize = error "i >= xsize in cube_at"
- | j < 0 = error "j < 0 in cube_at"
- | j >= ysize = error "j >= ysize in cube_at"
- | k < 0 = error "k < 0 in cube_at"
- | k >= zsize = error "k >= zsize in cube_at"
- | otherwise = Cube delta i j k fvs' tet_vol
- where
- fvs = function_values g
- (xsize, ysize, zsize) = dims fvs
- fvs' = make_values fvs i j k
- delta = h g
- tet_vol = (1/24)*(delta^(3::Int))
+cube_at !g !i !j !k =
+ Cube delta i j k fvs' tet_vol
+ where
+ fvs = function_values g
+ fvs' = make_values fvs i j k
+ delta = h g
+ tet_vol = (1/24)*(delta^(3::Int))
+
-- The first cube along any axis covers (-h/2, h/2). The second
-- covers (h/2, 3h/2). The third, (3h/2, 5h/2), and so on.
-- Since our grid is rectangular, we can figure this out without having
-- to check every cube.
find_containing_cube :: Grid -> Point -> Cube
-find_containing_cube g p =
+find_containing_cube g (Point x y z) =
cube_at g i j k
where
- (x, y, z) = p
i = calculate_containing_cube_coordinate g x
j = calculate_containing_cube_coordinate g y
k = calculate_containing_cube_coordinate g z
m' = (fromIntegral m) / (fromIntegral sfx) - offset
n' = (fromIntegral n) / (fromIntegral sfy) - offset
o' = (fromIntegral o) / (fromIntegral sfz) - offset
- p = (m', n', o') :: Point
+ p = Point m' n' o'
cube = find_containing_cube g p
t = find_containing_tetrahedron cube p
f = polynomial t
zoom v3d scale_factor
| xsize == 0 || ysize == 0 || zsize == 0 = empty3d
| otherwise =
- R.force $ R.unsafeTraverse v3d transExtent f
+ R.compute $ R.unsafeTraverse v3d transExtent f
where
(xsize, ysize, zsize) = dims v3d
transExtent = zoom_shape scale_factor
test_trilinear_f0_t0_v0 :: Assertion
test_trilinear_f0_t0_v0 =
- assertEqual "v0 is correct" (v0 t) (1, 1, 1)
+ assertEqual "v0 is correct" (v0 t) (Point 1 1 1)
test_trilinear_f0_t0_v1 :: Assertion
test_trilinear_f0_t0_v1 =
- assertEqual "v1 is correct" (v1 t) (0.5, 1, 1)
+ assertEqual "v1 is correct" (v1 t) (Point 0.5 1 1)
test_trilinear_f0_t0_v2 :: Assertion
test_trilinear_f0_t0_v2 =
- assertEqual "v2 is correct" (v2 t) (0.5, 0.5, 1.5)
+ assertEqual "v2 is correct" (v2 t) (Point 0.5 0.5 1.5)
test_trilinear_f0_t0_v3 :: Assertion
test_trilinear_f0_t0_v3 =
- assertClose "v3 is correct" (v3 t) (0.5, 1.5, 1.5)
+ assertEqual "v3 is correct" (v3 t) (Point 0.5 1.5 1.5)
test_trilinear_reproduced :: Assertion
test_trilinear_reproduced =
assertTrue "trilinears are reproduced correctly" $
- and [p (i', j', k') ~= value_at trilinear i j k
+ and [p (Point i' j' k') ~= value_at trilinear i j k
| i <- [0..2],
j <- [0..2],
k <- [0..2],
test_zeros_reproduced :: Assertion
test_zeros_reproduced =
assertTrue "the zero function is reproduced correctly" $
- and [p (i', j', k') ~= value_at zeros i j k
+ and [p (Point i' j' k') ~= value_at zeros i j k
| i <- [0..2],
j <- [0..2],
k <- [0..2],
test_trilinear9x9x9_reproduced :: Assertion
test_trilinear9x9x9_reproduced =
assertTrue "trilinear 9x9x9 is reproduced correctly" $
- and [p (i', j', k') ~= value_at trilinear9x9x9 i j k
+ and [p (Point i' j' k') ~= value_at trilinear9x9x9 i j k
| i <- [0..8],
j <- [0..8],
k <- [0..8],
where
g = make_grid 1 naturals_1d
cube = cube_at g 0 18 0
- p = (0, 17.5, 0.5) :: Point
+ p = Point 0 17.5 0.5
t20 = tetrahedron cube 20