> Sent: Thursday, April 05, 2018 at 4:40 PM > From: "Jeff Newmiller" <jdnew...@dcn.davis.ca.us> > > the coef function. >
For the benefit of other novices, used the following command to read the documentation: ?coef Then tried and obtained: > cvalue100<-coef(graphmodelp~100) > cvalue100 NULL Then looked at the model values which of course correspond to original non-modelled values. graphmodelp 1 2 3 4 5 6 7 8 91.244636 69.457794 52.873083 40.248368 30.638107 23.322525 17.753714 13.514590 9 10 11 10.287658 7.831233 5.961339 This prompted to think that interpolation is required, but the function 'approx' only seems to perform constant interpolation. Is the correct thinking to find a function to perform interpolation, then find/write a function to differentiate the model at a specific value of x, to find gradient at that point? ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.