From john.maindonald at anu.edu.au  Tue Apr 26 07:44:26 2005
From: john.maindonald at anu.edu.au (John Maindonald)
Date: Tue Apr 26 07:44:38 2005
Subject: [Rd] Enhanced version of plot.lm()
In-Reply-To: <200504251000.j3PA01lD009332@hypatia.math.ethz.ch>
References: <200504251000.j3PA01lD009332@hypatia.math.ethz.ch>
Message-ID: <b21d1d1a13e8f82d4e1d44c233e9f76e@anu.edu.au>

The web page http://wwwmaths.anu.edu.au/~johnm/r/plot-lm/
now includes files:
plot.lm.RData: Image for file for plot6.lm, a version of plot.lm in 
which
   David Firth's Cook's distance vs leverage/(1-leverage) plot is plot 6.
   The tick labels are in units of leverage, and the contour labels are
   in units of absolute values of the standardized residual.

plot6.lm.Rd file: A matching help file

Comments will be welcome.

Another issue, discussed recently on r-help, is that when the model
formula is long, the default sub.caption=deparse(x$call) is broken
into multiple text elements and overwrites.  The only clean and
simple way that I can see to handle is to set a default that tests
whether the formula is broken into multiple text elements, and if it is
then omit it.  Users can then use their own imaginative skills, and
such suggestions as have been made on r-help, to construct
whatever form of labeling best suits their case, their imaginative
skills and their coding skills.

John Maindonald.


On 25 Apr 2005, at 8:00 PM, David Firth wrote:

> From: David Firth <d.firth@warwick.ac.uk>
> Date: 24 April 2005 10:23:51 PM
> To: John Maindonald <john.maindonald@anu.edu.au>
> Cc: r-devel@stat.math.ethz.ch
> Subject: Re: [Rd] Enhanced version of plot.lm()
>
>
> On 24 Apr 2005, at 05:37, John Maindonald wrote:
>
>> I'd not like to lose the signs of the residuals. Also, as
>> plots 1-3 focus on residuals, there is less of a mental
>> leap in moving to residuals vs leverage; residuals vs
>> leverage/(1-leverage) would also be in the same spirit.
>
> Yes, I know what you mean.  Mental leaps are a matter of 
> taste...pitfalls, etc, come to mind.
>
>>
>> Maybe, one way or another, both plots (residuals vs
>> a function of leverage, and the plot from Hinkley et al)
>> should go in.  The easiest way to do this is to add a
>> further which=6.  I will do this if the consensus is that
>> this is the right way to go.  In any case, I'll add the
>> Hinkley et al reference (author of the contribution that
>> includes p.74?) to the draft help page.
>
> Sorry, I should have given the full reference, which (in BibTeX format 
> from CIS) is
>
> @inproceedings{Firt:gene:1991,
>     author = {Firth, D.},
>     title = {Generalized Linear Models},
>     year = {1991},
>     booktitle = {Statistical Theory and Modelling. In Honour of Sir 
> David Cox, FRS},
>     editor = {Hinkley, D. V. and Reid, N. and Snell, E. J.},
>     publisher = {Chapman \& Hall Ltd},
>     pages = {55--82},
>     keywords = {Analysis of deviance; Likelihood}
> }
>
> David
>
John Maindonald             email: john.maindonald@anu.edu.au
phone : +61 2 (6125)3473    fax  : +61 2(6125)5549
Centre for Bioinformation Science, Room 1194,
John Dedman Mathematical Sciences Building (Building 27)
Australian National University, Canberra ACT 0200.


[Rd] Enhanced version of plot.lm()
John Maindonald