Message-ID: <AANLkTi=4iVOPHJNfGM=HDTRD=Q5pSkPE5Hoa16Q+R-mX@mail.gmail.com>
Date: 2010-12-22T17:49:25Z
From: Liviu Andronic
Subject: matrix indexing in 'for' loop?
In-Reply-To: <20101222123927.19885gb5lgoo7dfz@mail.msu.edu>
On Wed, Dec 22, 2010 at 6:39 PM, <govindas at msu.edu> wrote:
> Thank you both for your suggestions. I have another question - is there a
> specific way to access the individual elements of a 'list' variable? i.e.
>
> dmi = matrix(rnorm(20),4,5)
> soi = matrix(rnorm(20),4,5)
> pe = matrix(rnorm(20),4,5)
> y <- list(dmi, soi, pe)
>
> y[[1]]?? gives
> [,1]?????? [,2]?????? [,3]?????? [,4]?????? [,5]
> [1,] -0.54463900? 1.6732445 -0.3807847 -1.0460530 -0.8142748
> [2,] -0.49654004 -0.9634258? 0.9074139 -0.1576030 -1.2268558
> [3,] -1.61835766 -0.4240122? 0.3626670? 0.7182964? 0.1576446
> [4,] -0.06313983? 0.6743465 -1.9897107? 0.8027337 -1.4372131
>
> But, I am interested in accessing the 1st column of 'dmi' matrix here - not
> as dmi[,1] but in terms of 'y'. Is it possible with 'list' function or
> something else?
>
Is this what you need?
> y[[1]]
[,1] [,2] [,3] [,4] [,5]
[1,] 0.2523449 -1.26606999 0.27594223 -0.5158524 -0.599899
[2,] -1.9155409 0.01081565 0.44497873 0.1819517 1.187899
[3,] 0.7624774 0.31296468 -0.02187076 0.9389091 0.865527
[4,] -0.8082626 -1.44330148 1.32975075 0.1788399 1.204917
> y[[1]][,1]
[1] 0.2523449 -1.9155409 0.7624774 -0.8082626
Liviu