From: Pascal Nicolas <pn@univ-angers.fr>
Message-Id: <199506090729.JAA03487@vink.Univ-Angers.Fr>
Subject: Re: vector dot multiply
To: caml-list@pauillac.inria.fr (Liste de diffusion Caml)
Date: Fri, 9 Jun 95 9:29:41 METDST
In-Reply-To: <199506081716.NAA01690@thomas.ge.com>; from "U-E59264-Osman Buyukisik" at Jun 8, 95 1:16 pm
>
> Hi,
> What would be 1). elegant
> 2). efficient
> way to write a "dot multiply" function in caml-light?
> This is what I came up with but I am hoping for a better one :
>
> let dot a b = let rec dot_aux a b i sum =
> if i< vect_length a then
> dot_aux a b (i+1) (sum +. (a.(i) *. b.(i)) )
> else
> sum
> in
> dot_aux a b 0 0.0;;
>
In order to avoid to (re)compute the length of a at each recursive call, you
can modify a little your function as follows
let dot a b = let rec dot_aux a b i sum L =
if i < L then
dot_aux a b (i+1) (sum +. (a.(i) *. b.(i))) L
else
sum
in dot_aux a b 0 0.0 (vect_length a) ;;
-- Pascal NICOLAS LERIA Université d'ANGERS Tél : (33) 41 73 54 20 2, Bd Lavoisier 49045 ANGERS cedex 01 FRANCE E Mail : pn@univ-angers.fr WWW Url : http://www.univ-angers.fr/~pn/nicolas.html