Arjun Bhandari <arb.em <at> adia.ae> writes: > I conduct a univariate regression with lm function. I would like to get > the p value for the regression. Is there a method that would enable me to > extract the p value into a variable.
# From lm docs (Sorry, Annette, for misusing your data) ctl <- c(4.17,5.58,5.18,6.11,4.50,4.61,5.17,4.53,5.33,5.14) trt <- c(4.81,4.17,4.41,3.59,5.87,3.83,6.03,4.89,4.32,4.69) lm.D90 <- lm(ctl ~ trt) # let's look if it is in lm.. str(lm.D90) # mmm.. looks like there are no p-test results # try summary sum.lm = summary(lm.D90) sum.lm # .. coming closer. # Colum Pr(>|t|), row trt is what we are looking for # Let's look into the structure str(sum.lm) # $coeffients has the wanted sum.lm$coefficients # looks good. We could use this, but better use the accessor function # Check the documentation, but coef is always a good try cf = coef(sum.lm) #now pick the right column pslope = cf["trt","Pr(>|t|)"] pslope ## # Could also use index, but less safe in general, even if the # "Pr(.." is definitively ugly cf[2,4] # In general, the $ approach is not recommened, if there is an # accessor funtion, use it. The closest (with no p-values) is confint(lm.D90) # Which probably tells more than the beloved p-values. # The better the journal's referees, the more they prefer confints over p ______________________________________________ R-help@stat.math.ethz.ch 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.
