[R] How to refer the element in a named list?

[David Winsemius]

On Sep 6, 2009, at 1:35 PM, Duncan Murdoch wrote:

> On 06/09/2009 1:04 PM, Peng Yu wrote:
>> Hi,
>> I thought that 'coefficients' is a named list, but I can not refer to
>> its element by something like r$coefficients$y. I used str() to check
>> r. It says the following. Can somebody let me know what it means?
>
> The line that matters is the one
>
> $ coefficients : Named num [1:2] 1.12e-15 1.00
>
> It says that coefficients is a numeric ("num") vector, not a list.   
> So r$coefficients["y"] will extract the y coefficient.
>

And r$coefficients[`(Intercept)`] # note back-quote, should get you  
the intercept

?coef

Generally coef(fit) will extract model coefficients across a wider  
range of R model objects.


> Duncan Murdoch
>
>
>>  ..- attr(*, "names")= chr [1:2] "(Intercept)" "y"
>> $ Rscript lm.R
>>> x=1:10
>>> y=1:10
>>> r=lm(x~y)
>>> class(r)
>> [1] "lm"
>>> mode(r)
>> [1] "list"
>>> r
>> Call:
>> lm(formula = x ~ y)
>> Coefficients:
>> (Intercept)            y
>>  1.123e-15    1.000e+00
>>> r$coefficients[1]
>> (Intercept)
>> 1.123467e-15
>>> r$coefficients[[1]]
>> [1] 1.123467e-15
>>> r$coefficients[2]
>> y
>> 1
>>> r$coefficients[[2]]
>> [1] 1
>>> str(r)
>> List of 12
>> $ coefficients : Named num [1:2] 1.12e-15 1.00
>>  ..- attr(*, "names")= chr [1:2] "(Intercept)" "y"
>> Regards,
>> Peng
>> ______________________________________________
>> 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.

David Winsemius, MD
Heritage Laboratories
West Hartford, CT