Hi Paul, >> Have you ever seen a drawing of the regions of an R plot with the >> terminology that is used for parts?
>From what I can remember, several documents on CRAN cover this. The one that springs to mind is Alzola & Harrell's "An Introduction to S and the Hmisc and Design Libraries,” which you can download from the Contributed Documentation link on CRAN. Chap. 4 of MASS by Venables & Ripley (4th ed.) will also give you what you want. Regards, Mark. Paul Johnson-11 wrote: > > On Fri, Feb 13, 2009 at 3:14 PM, Marc Schwartz > <marc_schwa...@comcast.net> wrote: >> on 02/13/2009 02:19 PM Paul Johnson wrote: >>> On Fri, Feb 13, 2009 at 1:51 PM, Marc Schwartz >> >> OK, so given all of the above, something like the following should work: >> >> set.seed(1233240) >> x <- rnorm(100) >> z <- gl(2,50) >> y <- rnorm(100, mean = 1.8 * as.numeric(z)) >> >> # Calculate a new range, subtracting a definable value >> # from the min of each vector for the new minimum >> # Adust the 0.25 as may be needed >> X <- c(min(x) - 0.25, max(x)) >> Y <- c(min(y) - 0.25, max(y)) >> >> # Use 'X' and "Y' here, not 'x' and 'y' >> # So that the plot region is extended appropriately >> plot(X, Y, type = "n", axes = F, xlab = "x", ylab = "y") >> >> points(x, y, pch = "$", cex = 0.7, col = z) >> >> # DO use 'pos'... >> axis(1, pos = Y[1], col = "green", col.axis = "green") >> axis(2, pos = X[1], col = "red", col.axis = "red") >> >> # get the plot region boundaries >> usr <- par("usr") >> >> segments(X[1], usr[3], X[1], usr[4], col = "red") >> segments(usr[1], Y[1], usr[2], Y[1], col = "green") >> >> >> HTH, >> >> Marc >> >> > > Thanks, Marc and everybody. > > This last suggestion produces the graph I was trying for. > > The other approaches that people suggest, using pos or xaxp, produce > other undesired changes in the tick marks or the position of the axes > relative to the data. xaxp offers the promise of a more intuitive > solution, except that, when using it, the tick marks are pushed off in > a bad way. Your use of segments to draw the extensions of the axes > was the first intuition I had, but I did not know about the trick you > used to retrieve the size of the usr box. > > More secrets of par, revealed. > > Have you ever seen a drawing of the regions of an R plot with the > terminology that is used for parts? Until I saw your example code, I > had not understood that the plot axes are placed at the absolute edge > of the user plotting region, for example. > > -- > Paul E. Johnson > Professor, Political Science > 1541 Lilac Lane, Room 504 > University of Kansas > > ______________________________________________ > 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. > > -- View this message in context: http://www.nabble.com/I-want-axes-that-cross-tp22003252p22033868.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.