[R] Obtaining values of estimates from a regression; How do I get values from a list?

[Eric Berger]

You have some choices

fitchange$coefficients[2]

zz$coefficients[2,1]

Note that class(zz$coefficients) shows that it is a matrix.

HTH,
Eric


On Fri, Feb 22, 2019 at 9:45 AM Sorkin, John <jsorkin using som.umaryland.edu>
wrote:

> I am trying to obtain the coefficients from a regression (performed using
> lm).  I would like to get the value for the slope (i.e. estimate) for pre
> from the following regression:
>
>
> fitchange <- lm(post-pre~pre,data=mydata2)
>
>
> I have tried the following without any success:
>
>
> zz <- summary(fitchange)["coefficients"]
> class(zz)
> print(zz)
> zz[[2,1]]
> zz[2,1]
> zz["pre","Estimate"]
>
>
> I clearly don't know how to select elements from the list returned by the
> summary function.
>
>
> A reproducible version of my code follows:
>
>
> mydata2 <-structure(list(pre = c(71.3302299440613, 86.2703384845455,
> 120.941698468568,
>                               80.9020778388552, 84.9927752038908,
> 77.9108032451793, 111.007107108483,
>                               93.288442414475, 126.097826796255,
> 111.63734644637),
>                          post = c(45.9294556667686,
>                                 114.661937978585, 138.501558726477,
> 55.355775963925, 97.7906200355594,
>                                 71.1008233796004, 149.308274695789,
> 122.828428213951, 143.690814568562,
>                                 116.607579975539)), class = "data.frame",
> row.names = c(NA, -10L))
>
> fitchange <- lm(post-pre~pre,data=mydata2)
> zz <- summary(fitchange)["coefficients"]
> class(zz)
> print(zz)
> zz[[2,1]]
> zz[2,1]
> zz["pre","Estimate"]
>
>
> Any help you can offer would be appreciated.
>
>
>
>
>
>
> John David Sorkin M.D., Ph.D.
> Professor of Medicine
> Chief, Biostatistics and Informatics
> University of Maryland School of Medicine Division of Gerontology and
> Geriatric Medicine
> Baltimore VA Medical Center
> 10 North Greene Street
> GRECC (BT/18/GR)
> Baltimore, MD 21201-1524
> (Phone) 410-605-7119
> (Fax) 410-605-7913 (Please call phone number above prior to faxing)
>
>
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>
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