David Winsemius <dwinsemius <at> comcast.net> writes: > > > On Nov 19, 2013, at 10:59 AM, Calum wrote: > > > Hi there, > > I hope someone can help me. > > > > I have a dataset of Concentration against Mortality, and I am trying to > > compare the use of Logit and Probit models using this data.
[snip snip snip] There are three ways you can get the inverse-link function 1. dig into the family object: binomial(link="probit")$linkinv 2. know that the probit link is the qnorm() (Normal quantile) function, and the inverse-probit is pnorm() (the Normal CDF). (Similarly, it seems that a lot of users don't know that plogis()/qlogis() similarly provide the logistic and logit functions ... 3. As David Winsemius suggests, use predict(...,type="response") (but options #1 and #2 are useful in providing flexibility). ______________________________________________ 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.
