From: Michael Orlitzky Date: Tue, 4 Oct 2011 14:51:52 +0000 (-0400) Subject: Fix value_at for 2d slices. X-Git-Tag: 0.0.1~107 X-Git-Url: https://gitweb.michael.orlitzky.com/?a=commitdiff_plain;h=2af8560d6b29fa9acd861f67473096e026529da3;p=spline3.git Fix value_at for 2d slices. --- diff --git a/src/FunctionValues.hs b/src/FunctionValues.hs index 8400c80..74e2123 100644 --- a/src/FunctionValues.hs +++ b/src/FunctionValues.hs @@ -135,6 +135,7 @@ empty_values :: FunctionValues empty_values = FunctionValues 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 + -- | The eval function is where the magic happens for the -- FunctionValues type. Given a 'Cardinal' direction and a -- 'FunctionValues' object, eval will return the value of the @@ -175,6 +176,7 @@ eval f (Difference x y) = (eval f x) - (eval f y) eval f (Product x y) = (eval f x) * (eval f y) eval f (Quotient x y) = (eval f x) / (eval f y) + -- | Takes a three-dimensional list of 'Double' and a set of 3D -- coordinates (i,j,k), and returns the value at (i,j,k) in the -- supplied list. If there is no such value, we calculate one @@ -207,25 +209,46 @@ value_at v3d i j k -- have been added where the indices are one-too-big. These are the -- "one index is bad" cases. | not (valid_i i) = - if (i == -1) + if (dim_i == 1) then - 2*(value_at v3d 0 j k) - (value_at v3d 1 j k) + -- We're one-dimensional in our first coordinate, so just + -- return the data point that we do have. If we try to use + -- the formula from remark 7.3, we go into an infinite loop. + value_at v3d 0 j k else - 2*(value_at v3d (i-1) j k) - (value_at v3d (i-2) j k) + if (i == -1) + then + 2*(value_at v3d 0 j k) - (value_at v3d 1 j k) + else + 2*(value_at v3d (i-1) j k) - (value_at v3d (i-2) j k) | not (valid_j j) = - if (j == -1) + if (dim_j == 1) then - 2*(value_at v3d i 0 k) - (value_at v3d i 1 k) + -- We're one-dimensional in our second coordinate, so just + -- return the data point that we do have. If we try to use + -- the formula from remark 7.3, we go into an infinite loop. + value_at v3d i 0 k else - 2*(value_at v3d i (j-1) k) - (value_at v3d i (j-2) k) + if (j == -1) + then + 2*(value_at v3d i 0 k) - (value_at v3d i 1 k) + else + 2*(value_at v3d i (j-1) k) - (value_at v3d i (j-2) k) | not (valid_k k) = - if (k == -1) + if (dim_k == 1) then - 2*(value_at v3d i j 0) - (value_at v3d i j 1) + -- We're one-dimensional in our third coordinate, so just + -- return the data point that we do have. If we try to use + -- the formula from remark 7.3, we go into an infinite loop. + value_at v3d i j 0 else - 2*(value_at v3d i j (k-1)) - (value_at v3d i j (k-2)) + if (k == -1) + then + 2*(value_at v3d i j 0) - (value_at v3d i j 1) + else + 2*(value_at v3d i j (k-1)) - (value_at v3d i j (k-2)) | otherwise = let istr = show i @@ -235,16 +258,16 @@ value_at v3d i j k in error $ "value_at called outside of domain: " ++ coordstr where - (xsize, ysize, zsize) = dims v3d + (dim_i, dim_j, dim_k) = dims v3d valid_i :: Int -> Bool - valid_i i' = (i' >= 0) && (i' < xsize) + valid_i i' = (i' >= 0) && (i' < dim_i) valid_j :: Int -> Bool - valid_j j' = (j' >= 0) && (j' < ysize) + valid_j j' = (j' >= 0) && (j' < dim_j) valid_k :: Int -> Bool - valid_k k' = (k' >= 0) && (k' < zsize) + valid_k k' = (k' >= 0) && (k' < dim_k)