From simon.urbanek at r-project.org  Thu Dec 30 16:03:53 2010
From: simon.urbanek at r-project.org (Simon Urbanek)
Date: Thu, 30 Dec 2010 10:03:53 -0500
Subject: [Rd] key-value mapping in C inside R?
In-Reply-To: <4D1C8012.7050403@naufraghi.net>
References: <4D1C8012.7050403@naufraghi.net>
Message-ID: <59A3C41D-ADC8-4B67-B83E-97E490B491FE@r-project.org>


On Dec 30, 2010, at 7:50 AM, Matteo Bertini wrote:

> I'm testing some modifications in arima.c.
> I've noticed that a big internal array of double (rbar) is usually sparse and I'd like to add an option to store it as key-value mapping.
> 
> Is there a library function or some other approach already used inside the R core for key-value mappings?
> 

environment created with hash=TRUE, e.g.:
e = new.env(TRUE, emptyenv())
e[["foo"]] = "bar"

You can even set "size" with the expected size if you know it in advance.

Cheers,
Simon



[Rd] key-value mapping in C inside R?
Simon Urbanek