From: Michael Orlitzky Date: Mon, 3 Oct 2011 02:14:14 +0000 (-0400) Subject: Use a slightly more stable (I think?) formula for the {x,y,z}{min,max}. X-Git-Tag: 0.0.1~114 X-Git-Url: https://gitweb.michael.orlitzky.com/?a=commitdiff_plain;h=279936ce0f59cbc2b5c1c3c748ae9fae03ee1146;p=spline3.git Use a slightly more stable (I think?) formula for the {x,y,z}{min,max}. --- diff --git a/src/Cube.hs b/src/Cube.hs index 83f4da3..3a997a4 100644 --- a/src/Cube.hs +++ b/src/Cube.hs @@ -74,7 +74,7 @@ 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 +82,7 @@ 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 +90,7 @@ 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 +98,7 @@ 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 +106,7 @@ 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 +114,7 @@ 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