Hi Cetin,
This is probably the easiest way:
> (m - es)^2/es
listMatrix (2,2)
[0.6163270413689804,0.600918865334756,0.33217626255600896,0.3238718559921087
]
This will create 2 temporary arrays. Alternatively,
> let res = listMatrix (shape m) [ (o-e)^2 / e | o <- colElems m | e
<- colElems es ] where colElems = concatMap elems . cols
> res
listMatrix (2,2)
[0.6163270413689804,0.600918865334756,0.33217626255600896,0.3238718559921087
]
In a later version of the library, "colElems" will probably be built-
in. This version has the disadvantage that it doesn't use BLAS calls.
If you *really* want to get tricky and eliminate temporary arrays:
> runSTMatrix $ do
res <- newCopyMatrix m
subMatrix res es
modifyWith (^2) res
divMatrix res es
return res
Now, to get the sum:
> sumAbs $ vectorFromMatrix res
1.8732940252518542
or
> sum $ elems res
1.8732940252518542
The first version will usually be more efficient, since it calls the
BLAS1 function "dasum".
Patrick
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