Re: [R] gam plots and seWithMean

2010-10-25 Thread Greg Dropkin
hadn't realised the answer would be in the source code! anyway, this appears to work. The only difference is in the last section. greg -- library(mgcv) #simulate some data x1<-runif(500) x2<-rnorm(500) x3<-rpois(500,3) d<-runif(500) t<-runif(500,20,50) linp<--6.5+x1+2*x2-x3+2*exp(-2*d)*sin(2*p

[R] gam plots and seWithMean

2010-10-21 Thread Greg Dropkin
hello I'm learning mgcv and would like to obtain numerical output corresponding to plot.gam. I can do so when seWithMean=FALSE (the default) but only approximately when seWithMean=TRUE. Can anyone show how to obtain the exact values? Alternatively, can you clarify the explanation in the manual

Re: [R] GAM plots

2009-11-27 Thread Simon Wood
Are you using mgcv:::gam? To get plot data suitable for making plots of smooth effects, you probably need to use `predict.gam' to evaluate the smooth curves (and standard errors) at a nice regular set of points for plotting. Also don't forget that the residuals shown on plot.gam are the `partial

[R] GAM plots

2009-11-21 Thread Joe Trubisz
Hello all... I'm attempting to write my own GAM plot function, so I can overlay it on top of an already existing plot. Problem is that after I do the gam, e.g. m<-gam(...), I cannot match the graph that gam.plot outputs when I attempt to plot the values from m$residuals, m$linear.predict