From edd at debian.org  Fri Jun  6 07:41:50 2003
From: edd at debian.org (Dirk Eddelbuettel)
Date: Fri Jun  6 13:42:12 2003
Subject: [Rd] irregular time-series
In-Reply-To: <8CBAA121CEB4D5118CB200508BB2BBEF540368@xmx8lonib.lonib.commerzbank.com>
References: <8CBAA121CEB4D5118CB200508BB2BBEF540368@xmx8lonib.lonib.commerzbank.com>
Message-ID: <20030606114150.GA15205@sonny.eddelbuettel.com>

On Fri, Jun 06, 2003 at 09:46:04AM +0100, Heywood, Giles wrote:
> I make quite a lot of use of irregular time-series, and had already spent a
> bit of time writing an 'its' class when the 'irts' class was released via
> the package 'tseries'.
> 
> I have experimented with the 'irts' class, and have some practical issues
> with its use.  In some applications of irregular time-series (in my case
> these are financial and econometric) there are many instances where it is
> useful to consider them as an extension (subclass) of the class 'matrix',
> using S4 class inheritance.  This is also useful in printing. 
> 
> The 'its' class I have written is an S4 extension of the matrix class, using
> a single slot for a POSIX  dates vector, which time-indexes the rows.  The
> practical advantage of this, compared to the 'irts' class, is that the
> matrix methods are inherited.
> 
> In addition to file operations and some simple functions, I have also
> written a number of method extensions for this 'its' class, including [.its,
> [[.its, intersect, union, diff, lag.
> 
> Is there value in such a package, given the resemblance of 'its' to the
> existing 'irts' class?  I would be happy to contribute it, and provide some
> maintenance.

Yes, please! Either inside tseries, assuming Adrian is happy with that, or
outside. 

I use the 'padding irregular series with NAs' trick quite a bit and would
love to have its support.

Dirk

-- 
Don't drink and derive. Alcohol and analysis don't mix.


[Rd] irregular time-series
Dirk Eddelbuettel