Thank you for your answer, but the function spline() (and a lot of other function in R) can't take in its parameters the original contour which are define by a vector, i.e. :
##creation of breaks for colors i<-1 paliers <- c(-1.0E300) while(i<=length(level[,1])) { paliers <- c(paliers,level[i,1]) i <- i+1 } paliers <- c(paliers, 1.0E300) Le 17 mai 2011 à 13:05, Duncan Murdoch a écrit : > On 11-05-17 5:58 AM, Pierre Bruyer wrote: >> I'm a French developer (so I am sorry if my english is not perfect). I have >> a problem to smooth the contours of a map. I have a dataset with 3 columns, >> x, y and z, where x and y are the coordinates of my points and z is evaluate >> to a qualitative elevation and his representation is a set of colors, which >> is define by levels. >> >> The problem is the curve of my contour is so linear, and I would like a more >> continuous contour. I use the function fitted.contour to draw my map. > > If you use a finer grid of x,y values you'll get shorter segments and they > will look smoother. > > You might be able to use a smooth interpolator (e.g. spline()) rather than > linear interpolation, but those occasionally do strange things e.g. > > x <- c(1:4, 5.9, 6:10) > y <- c(1:4, 7, 6:10) > plot(spline(x,y, n=200), type="l") > points(x,y) > > where one point is out of line with the others, but the curve overcompensates > in order to stay smooth. > > Duncan Murdoch ______________________________________________ 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.