Modification of the above to use FlVector did not show a difference.
On Sun, Jan 20, 2013 at 2:35 PM, Jens Axel Søgaard <jensa...@soegaard.net>wrote: > 2013/1/20 Berthold Bäuml <berthold.bae...@dlr.de>: > >> Ah! The Numpy example uses floats and not doubles. > > > > On my machine Numpy says it is using float64, hence, double. > > big1.dtype.name -> float64 > > Sorry for the confusion. I am used to the Racket documentation > were float means single precision, so I misinterpreted the Numpy > documentation. > > Also > > > numpy.random.random((5,5)) > array([[ 0.04748764, 0.15242073, 0.2366255 , 0.86926654, 0.16586114], > [ 0.33117124, 0.7504899 , 0.43179013, 0.1992083 , 0.83266119], > [ 0.25741902, 0.36912007, 0.38273193, 0.29622522, 0.75817261], > [ 0.49313726, 0.20514653, 0.45329344, 0.964105 , 0.77459153], > [ 0.5267172 , 0.87269101, 0.34530438, 0.38218051, 0.05107181]]) > > suggested, that the numbers were single precision. It turns out > that random only produces 53 bit random floats. > > Anyways, here is a standard matrix multiplication algorithm in > Typed Racket. > > #lang typed/racket > (require racket/unsafe/ops > racket/flonum) > > (define-type NF Nonnegative-Fixnum) > > (: matrix* : > (Vectorof Flonum) (Vectorof Flonum) Index Index Index > -> (Vectorof Flonum)) > (define (matrix* A B m p n) > (define size (* m n)) > (define: v : (Vectorof Flonum) (make-vector size 0.0)) > (define index 0) > (: loop-i : NF -> (Vectorof Flonum)) > (define (loop-i i) > (cond [(< i m) > (loop-j i 0) > (loop-i (+ i 1))] > [else v])) > (: loop-j : NF NF -> Void) > (define (loop-j i j) > (when (< j n) > (loop-k i j 0 0.0) > (set! index (+ index 1)) > (loop-j i (+ j 1)))) > (: loop-k : NF NF NF Flonum -> Void) > (define (loop-k i j k sum) > (define i*p (* i p)) > (define k*n (* k n)) > (cond > [(< k p) > (loop-k i j (+ k 1) > (+ sum > (* (unsafe-vector-ref A (+ i*p k)) > (unsafe-vector-ref B (+ k*n j)))))] > [else > (vector-set! v index sum)])) > (loop-i 0)) > > (define dim 200) > (define A (build-vector (* dim dim) (λ (_) (random)))) > (define B (build-vector (* dim dim) (λ (_) (random)))) > (collect-garbage) > (collect-garbage) > (define A*B (time (matrix* A B dim dim dim))) > > /Jens Axel > > ____________________ > Racket Users list: > http://lists.racket-lang.org/users >
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