Readers, I have looked at various documents hosted on the web site; I couldn't find anything on interpolation. So I started r and accessed the help (help.start()). (by the way is it possible to configure r to open help in opera instead of firefox?) Initially I read the help for the akima package but couldn't understand it. Next I tried the asplines package help.
I tried to copy the example: x<-c(-3,-2,... I realised that the 'n=...' parameter determines the resolution of the line, so I practised the following subsequent commands: > x<-c(-3,-2,-1,0,1,2,2.5,3) > y<-c(0,0,0,0,-1,-1,0,2) > plot(x,y,ylim=c(-3,3)) I get the graph as expected Then I enter further commands: lines(spline(x,y,n=200),col="blue") lines(spline(x,y,n=20),col="blue") lines(spline(x,y,n=2),col="blue") lines(spline(x, y, n=5), col="blue") >From this I learn that n corresponds to line resolution. :) However I could not find a way to remove the last 3 commands and then show only the first line. How do I achieve this please? I am learning this package in order to perform my next task; interpolation. If I have a linear relationship between two variables and plot the results, how do I manipulate the graph to be able to show a value of the abscissa, especially for negative values, i.e. where the linear line intersects the x axis left of the y axis? There are 4 packages that claim interpolation (akima, aspline, interp, interpp) but they seem far to complicated, especially the latter two. Is there a simpler package I could use? Yours, rh...@conference.jabber.org r 251 (27-06-07) mandriva 2008 ______________________________________________ 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.
