X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=src%2FMisc.hs;h=9dcbac943b41c52f06b5140bfef8636eaafbb3e7;hb=cb5b361ea78acd6f8c04cd864adc15edd90299db;hp=48482b4f69a2cfe580b8b34a605beae82565168b;hpb=effb6b9a8716ce58fed6c8260c57164601a7df30;p=spline3.git

diff --git a/src/Misc.hs b/src/Misc.hs
index 48482b4..9dcbac9 100644
--- a/src/Misc.hs
+++ b/src/Misc.hs
@@ -25,10 +25,30 @@ factorial n
 
 -- | Takes a three-dimensional list, and flattens it into a
 --   one-dimensional one.
+--
+--  Examples:
+--
+--  >>> flatten [ [[1,2], [3,4]], [[5,6], [7,8]] ]
+--  [1,2,3,4,5,6,7,8]
+--
 flatten :: [[[a]]] -> [a]
 flatten xs = concat $ concat xs
 
 
+-- | Switch the x and z dimensions of a three-dimensional list.
+transpose_xz :: [[[a]]] -> [[[a]]]
+transpose_xz [] = []
+transpose_xz [[]] = [[]]
+transpose_xz [[[]]] = [[[]]]
+transpose_xz m =
+    [[[ m !! x !! y !! z | x <- [0..xsize]]
+                      | y <- [0..ysize]]
+                      | z <- [0..zsize]]
+    where
+      zsize = (length m) - 1
+      ysize = length (head m) - 1
+      xsize = length (head $ head m) - 1
+
 -- | Takes a list, and returns True if its elements are pairwise
 --   equal. Returns False otherwise.
 all_equal :: (Eq a) => [a] -> Bool