From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <krohrer@student.ethz.ch>
X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on yquem.inria.fr
X-Spam-Level: 
X-Spam-Status: No, score=0.0 required=5.0 tests=none autolearn=disabled 
	version=3.1.3
X-Original-To: caml-list@yquem.inria.fr
Delivered-To: caml-list@yquem.inria.fr
Received: from concorde.inria.fr (concorde.inria.fr [192.93.2.39])
	by yquem.inria.fr (Postfix) with ESMTP id 46E43BC0A
	for <caml-list@yquem.inria.fr>; Wed, 20 Jun 2007 04:47:21 +0200 (CEST)
Received: from XSMTP0.ethz.ch (xsmtp0.ethz.ch [82.130.70.14])
	by concorde.inria.fr (8.13.6/8.13.6) with ESMTP id l5K2lKfs027982
	for <caml-list@yquem.inria.fr>; Wed, 20 Jun 2007 04:47:21 +0200
Received: from xfe1.d.ethz.ch ([82.130.124.41]) by XSMTP0.ethz.ch with Microsoft SMTPSVC(6.0.3790.3959);
	 Wed, 20 Jun 2007 04:47:18 +0200
Received: from [10.0.1.3] ([80.219.210.76]) by xfe1.d.ethz.ch over TLS secured channel with Microsoft SMTPSVC(6.0.3790.3959);
	 Wed, 20 Jun 2007 04:47:18 +0200
Mime-Version: 1.0 (Apple Message framework v752.3)
Content-Transfer-Encoding: 7bit
Message-Id: <47EE749E-06C8-4A20-8D38-EE47D43CBCA6@student.ethz.ch>
Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed
To: caml-list@yquem.inria.fr
From: Kaspar Rohrer <krohrer@student.ethz.ch>
Subject: FFI: Allocating an array of doubles and initializing it
Date: Wed, 20 Jun 2007 04:47:15 +0200
X-Mailer: Apple Mail (2.752.3)
X-OriginalArrivalTime: 20 Jun 2007 02:47:18.0144 (UTC) FILETIME=[511CB800:01C7B2E5]
X-Miltered: at concorde with ID 46789538.000 by Joe's j-chkmail (http://j-chkmail . ensmp . fr)!
X-Spam: no; 0.00; ffi:01 allocating:01 initializing:01 ocaml:01 camlprim:01 camlparam:01 val:01 val:01 alloc:01 wosize:01 camlreturn:01 ocaml:01 caml:02 seems:03 float:03 

Hello,

I'm currently trying to allocate an array of doubles to pass some  
values back to Ocaml. However, documentation on this specific topic  
seems relatively sparse, and thus I'm not sure if the following is  
correct:

CAMLprim value ml_create_float_array (value n, value fill)
{
	CAMLparam2(n, fill);
	CAMLlocal1(arr);

	long i;
	long N = Long_val(n);
	double D = Double_val(fill);
	
	arr = caml_alloc_shr(N * Double_wosize, Double_array_tag);
	for (i = 0; i < N; ++i) {
	   Store_double_field(arr, i, D);
	}
	
	CAMLreturn(arr);
}

Any help appreciated.
	Kaspar Rohrer

PS: I'm using Ocaml 3.09.