Dear all, I'm trying to fit a soap film smoother by mgcv, accounting for a polygonal boundary. Everything works well untill I plot the results, when I get the right shape, but plot coordinates are exchanged. Function vis.gam() doesn't run into the same problem. Here I enclose the script and attach an essential R workspace. Can anybody provide some help or hints? Regards, SA ##### # points, polygon, knots plot(aa[[1]]$lon,aa[[1]]$lat,type="l") points(knots,pch=20,col=2) points(data$lon,data$lat,pch=20,col="blue") ##### # data den <- data$den lon <- data$lon lat <- data$lat ##### # model require(mgcv) nmax <- 100 b <- gam(I(den^0.5)~s(lon,lat,k=30,bs="so",xt=list(bnd=aa,nmax=nmax)), knots=knots) ##### # default plot x11() plot(b) # The plot shape is OK, but the coordinates are exchanged: # lon is in the range of lat and vice-versa