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From: Pierre Weis <weis@pauillac.inria.fr>
Message-Id: <199506081829.UAA01903@pauillac.inria.fr>
Subject: Re: vector dot multiply
To: osman.buyukisik@ae.ge.com (U-E59264-Osman Buyukisik)
Date: Thu, 8 Jun 1995 20:29:15 +0200 (MET DST)
Cc: caml-list@pauillac.inria.fr
In-Reply-To: <199506081716.NAA01690@thomas.ge.com> from "U-E59264-Osman Buyukisik" at Jun 8, 95 01:16:29 pm
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> Hi,
>  What would be 1). elegant
>                2). efficient  
>  way to write a "dot multiply" function in caml-light? 

You're recursive version seems good (except that you (re)compute
the vect_length of vector a at each recursive call). You may prefer an
imperative version (as yours, this function assumes a and b to have the
same length):

let dot a b =
  let s = ref 0.0 in
  for i = 0 to vect_length a - 1 do
   s := a.(i) *. b.(i) +. !s
  done;
  !s;;

> Also, is there a similar construct to Haskell array/list comprehensions?

No. This is very difficult to get in a strict language, where these
lists cannot be computed as necessary as is done in lazy languages...

Pierre Weis
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