[R] Two Noobie questions

[Neil Beddoe]

You can also use subscripts to get at things with a bit of playing around.

> summary(lm(x~seq(1,length(x),1)))

Call:
lm(formula = x ~ seq(1, length(x), 1))

Residuals:
     Min       1Q   Median       3Q      Max 
-40.0961 -15.5289  -0.6489  12.7488  41.0107 

Coefficients:
                       Estimate Std. Error t value Pr(>|t|)    
(Intercept)          165.259602   1.620906 101.955   <2e-16 ***
seq(1, length(x), 1)  -0.048711   0.005551  -8.775   <2e-16 ***
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1 

Residual standard error: 18.19 on 503 degrees of freedom
Multiple R-squared: 0.1328,     Adjusted R-squared: 0.131 
F-statistic:    77 on 1 and 503 DF,  p-value: < 2.2e-16 

> summary(lm(x~seq(1,length(x),1)))[[4]][[4]]
[1] 0.005551145
> summary(lm(x~seq(1,length(x),1)))[[4]][[2]]
[1] -0.04871091
> 

-----Original Message-----
From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf Of AllenL
Sent: 06 January 2009 19:48
To: r-help at r-project.org
Subject: Re: [R] Two Noobie questions


Thanks for your help!

I combined the above two to get the following, which seems to work (if somewhat inelegant):

int.List<-unlist(lapply(lmList, function(x) {coef(x)[1]}),use.names=FALSE) lmList is my list of lm objects. 
-Allen





David Winsemius wrote:
> 
> 
> On Jan 6, 2009, at 1:50 PM, AllenL wrote:
> 
>>
>> 1. I have a list of lm (linear model) objects. Is it possible to 
>> select, through subscripts, a particular element (say, the intercept) 
>> from all the models? I've tried something like this:
> 
> ?coef
> if your list of models is ml, then perhaps something like this  
> partially tested idea:
> 
> lapply(ml, function(x) coef(x)[1] )
> 
> This is what I get using that formulation an available logistic model:
> 
>  > coef(lr.TC_HDL_BMI)[1]
> Intercept
> -6.132448
> 
> 
>>
>>
>> List[[1:length(list)]][1]
>> All members of the list are similar. My goal is to have a list of the
>> intercepts and lists of other estimated parameters. Is it better to  
>> convert
>> to a matrix? How to do this?
>>
>> 2. Connected to this, how do I convert from a list back to a vector?  
>> This
>> problem arose from using "split" to split a vector by a factor, then
>> selecting a subset of this (ie. length>10), leaving me with subset  
>> list of
>> my original. Unsplit(newList, factor) doesn't work, presumably due  
>> to my
>> removal of some values. Thoughts?
> 
> ?unlist
> 
>  > ll <- list(1,2,3,4)
>  > ll
> [[1]]
> [1] 1
> 
> [[2]]
> [1] 2
> 
> [[3]]
> [1] 3
> 
> [[4]]
> [1] 4
> 
>  > unlist(ll)
> [1] 1 2 3 4
>  > str(unlist(ll))
>   num [1:4] 1 2 3 4
>  > is.vector(unlist(ll))
> [1] TRUE
> 
> -- 
> David Winsemius
>>
>>
>> Thanks!
>> -Allen
>>
>>
>>
>> -- 
>> View this message in context:
>> http://www.nabble.com/Two-Noobie-questions-tp21316554p21316554.html
>> Sent from the R help mailing list archive at Nabble.com.
>>
>> ______________________________________________
>> R-help at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide
>> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
> 
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
> 
> 

-- 
View this message in context: http://www.nabble.com/Two-Noobie-questions-tp21316554p21317630.html
Sent from the R help mailing list archive at Nabble.com.

______________________________________________
R-help at r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

.

This message is intended only for the use of the person(s) to whom it is addressed. It may contain information which is privileged and confidential. Accordingly any unauthorised use is strictly prohibited. If you are not the intended recipient, please contact the sender as soon as possible.

It is not intended as an offer or solicitation for the purchase or sale of any financial instrument or as an official confirmation of any transaction, unless specifically agreed otherwise. All market prices, data and other information are not warranted as to completeness or accuracy and are subject to change without notice. Any opinions or advice contained in this Internet email are subject to the terms and conditions expressed in any applicable governing Marble Bar Asset Management LLP's  terms and conditions of business or client agreement letter. Any comments or statements made herein do not necessarily reflect those of Marble Bar Asset Management LLP.

Marble Bar Asset Management LLP is regulated and authorised by the FSA.