R help - Oct 2010 - add diagonal line

Hi,

I would like to add a line on the diagonal of a covariance matrix, is there
a quick way to do it besides abline?

Thanks!

-- 
Marcelo Andrade de Lima
UNIFESP - Universidade Federal de São Paulo
Departamento de Bioquímica
Disciplina de Biologia Molecular
Rua Três de Maio 100, 4 andar - Vila Clementino, 04044-020
Lab +55 11 55764438 R.1188
Cell +55 11 92725274
mlima@unifesp.br

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On Oct 27, 2010, at 11:17 AM, Marcelo Lima wrote:
> Hi,
>
> I would like to add a line on the diagonal of a covariance matrix,  
> is there
> a quick way to do it besides abline?
It's somewhat unclear what you are doing. How are you "plotting"
this
covariance matrix?

Perhaps:
?segments

-- 

David Winsemius, MD
West Hartford, CT

On Wed, 2010-10-27 at 13:17 -0200, Marcelo Lima wrote:
> Hi,
> 
> I would like to add a line on the diagonal of a covariance matrix, is there
> a quick way to do it besides abline?
> 
> Thanks!
What's wrong with abline()? It does exactly what you want.

By the way,  reproducible example such as requested by David would
something like:

cmat <- matrix(rnorm(100), ncol = 10)
diag(cmat) <- 1
contour(1:10, 1:10, cmat)
abline(11, -1, col = "red", lwd = 2)
box()

I.e. some code with example data that shows us what you are trying to
do. It is not always possible to grep the meaning from a textual
description sufficiently well to be able to move from there to code.
This is discussed in the posting guide.

HTH

G

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