Is there a way to get the number of dimension of an array ? i.e. something like :
dims :: (Ix a) => Array a b -> Int dims = ... a = listArray (1,10) [1,2..] b = listArray ((1,1),(10,10)) [1,2..] dims a -- should be equal to 1 dims b -- should be equal to 2
The key is somewhere in the Ix class but where ? Fred -- ------------------------------------------------------- Dr. Frederic Nicolier Maitre de conferences, laboratoire LAM - URCA Animateur du projet ANITA : http://f.nicolier.free.fr/recherches/ Dept. GE&II, IUT de Troyes 9 rue de Quebec 10026 Troyes Cedex Tel: 03 25 42 71 01 Std: 03 25 42 46 46 Fax: 03 25 42 46 43 email: f.nicolier@iut-troyes.univ-reims.fr ---------------------------------------------------------
On Mon, 29 Mar 2004, Fred Nicolier wrote:
Is there a way to get the number of dimension of an array ? i.e. something like :
dims :: (Ix a) => Array a b -> Int dims = ... a = listArray (1,10) [1,2..] b = listArray ((1,1),(10,10)) [1,2..] dims a -- should be equal to 1 dims b -- should be equal to 2
The key is somewhere in the Ix class but where ?
In a sense Haskell arrays are always one dimensional. But as you noted tuples are used to achieve higher dimensionality. As far as I know there is no way of asking for the dimension of an array. You could write your own class for that though. Here's a suggestion: \begin{code} dims :: (Ix a, HasDimension a) => Array a b -> Int dims arr = dimension (head (range arr)) class HasDimension a where dimension :: a -> Int instance HasDimension Int where dimension _ = 1 instance HasDimension Float where dimension _ = 1 instance HasDimension (a,b) where dimension _ = 2 instance HasDimension (a,b,c) where dimension _ = 3 \end{code} And so forth. Beware. The code is untested. Hope this helps. /Josef
Josef Svenningsson wrote:
In a sense Haskell arrays are always one dimensional. But as you noted tuples are used to achieve higher dimensionality. As far as I know there is no way of asking for the dimension of an array. You could write your own class for that though. Here's a suggestion:
\begin{code} dims :: (Ix a, HasDimension a) => Array a b -> Int dims arr = dimension (head (range arr))
with the following correction, it is ok. dims arr = dimension (head (range $ bounds arr)) thanks at lot Fred -- ------------------------------------------------------- Dr. Frederic Nicolier Maitre de conferences, laboratoire LAM - URCA Animateur du projet ANITA : http://f.nicolier.free.fr/recherches/ Dept. GE&II, IUT de Troyes 9 rue de Quebec 10026 Troyes Cedex Tel: 03 25 42 71 01 Std: 03 25 42 46 46 Fax: 03 25 42 46 43 email: f.nicolier@iut-troyes.univ-reims.fr ---------------------------------------------------------
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Fred Nicolier -
Josef Svenningsson