Message-ID: <Pine.LNX.4.61.0504131718430.10084@gannet.stats>
Date: 2005-04-13T16:25:49Z
From: Brian Ripley
Subject: Behavior of apply() when used with start()
In-Reply-To: <10dee469050413073190a09e3@mail.gmail.com>
On Wed, 13 Apr 2005, Fernando Saldanha wrote:
> Can someone explain why starts1 and starts2 are diffferent in the example below?
Yes, at least one person can. Actually, anyone who looked could:
> arr
Time Series:
Start = 1
End = 3
Frequency = 1
tsa tsb
1 1 NA
2 2 2
3 3 3
Note the times series attributes apply to the whole matrix.
> After running this program
>
> a <- c(1:3)
> b <- c(2:3)
> tsa <- ts(a)
> tsb <- ts(b, start = 2)
> arr <- cbind(tsa, tsb)
> starts1 <- cbind(start(tsa), start(tsb))
> starts2 <- apply(arr, 2, start)
>
> I get:
>
>> starts1
> [,1] [,2]
> [1,] 1 2
> [2,] 1 1
>
>> starts2
> tsa tsb
> [1,] 1 1
> [2,] 1 1
--
Brian D. Ripley, ripley at stats.ox.ac.uk
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595