On 06/09/2009 1:45 PM, David Winsemius wrote:
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
No, that says to get the element of the coefficients whose index is
stored in a variable named `(Intercept)`. (Chances are that variable
doesn't exist, unless you made an effort to create it. And if you
perversely stored "y" in it you'd get the same coefficient as before!)
You want regular (single or double, R doesn't care) quotes to say that
you are giving the index directly:
r$coefficients["(Intercept)"]
Duncan Murdoch
?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
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______________________________________________
R-help@r-project.org mailing list
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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
______________________________________________
R-help@r-project.org mailing list
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
