> On 02-Mar-2012 IOANNA wrote: > > Hello, > > I run a linear regression I get the summary, e.g.: > > > >> > > Call: > > lm(formula = signal ~ conc) > > Residuals: > > 1 2 3 4 5 > > 0.4 -1.0 1.6 -1.8 0.8 > > Coefficients: > > Estimate Std. Error t value Pr(>|t|) > > (Intercept) 3.60000 1.23288 2.92 0.0615 . > > conc 1.94000 0.05033 38.54 3.84e-05 *** > > --- > > Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1 > > Residual standard error: 1.592 on 3 degrees of freedom > > Multiple R-Squared: 0.998, Adjusted R-squared: 0.9973 > > F-statistic: 1486 on 1 and 3 DF, p-value: 3.842e-0 > > > > I would like to call the probability of the t-test only in order > > to use it separately. For example I 'd like to get: > > Pr<-3.84e-05 > > > > Similarly I want to call the standard error of the parameters > > and the function: > > SEconc<-0.05033 > > > > I don't know how to do this. Any help? > > > > Regards, > > Ioanna
> Hi Ioanna, > If you look at '?summary.lm' and read the section "Value", > you will see that the returned value is a list with several > components, one of which is: > coefficients: a p x 4 matrix with columns for the > estimated coefficient, its standard error, > t-statistic and corresponding (two-sided) p-value. > Aliased coefficients are omitted. > This is effectively as displayed by summary(lm...)). > So your > Coefficients: > > Estimate Std. Error t value Pr(>|t|) > > (Intercept) 3.60000 1.23288 2.92 0.0615 . > > conc 1.94000 0.05033 38.54 3.84e-05 *** > (apart from the significance codes "." and "***") are the > elements in this p=2 x 4 matrix. indeed. > Hence > summary(lm.r)$coef > would give the full 4x4 matrix (you can abbreviate "coefficients" > to "coef"), Yes. In the present case, I tell all my "students" (:= everyone who wants to learn .. ;-) to use coef(summary(lm.r)) instead of summary(lm.r)$coef because using the coef() [or coefficients()] method will work with many more models and situations, notably also for cases where the (summary of the) fitted model is not a list (but e.g. a S4 class, reference class, ..), or does not store these in exactly this location. Martin > and so > summary(lm.r)$coef[2,4] > will give you the P-value for "conc", and > summary(lm.r)$coef[2,2] > will give the SE of the estimate of "conc". And so on. > Ted. > ------------------------------------------------- > E-Mail: (Ted Harding) <ted.hard...@wlandres.net> > Date: 02-Mar-2012 Time: 13:09:03 > This message was sent by XFMail > ______________________________________________ > R-help@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@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.
