"Bob and Deb" <[EMAIL PROTECTED]> writes: > I'm new to R and I have a problem :-) Below is what my data file that looks > like. I tried to import and contour this data by doing this: > > cv_data <- read.table("cv_data.csv",sep=",",header=TRUE) > attach(cv_data) > contour(x,y,z) > > I get the error "Error in contour.default(x,y,z) : increasing 'x', and 'y' > values expected" I can see that y is not increasing, but I don't know how > to get this to work.
All of your arguments to contour are wrong. x and y are the locations of the gridlines for the figure (and are not required), and z is a matrix of values, not a single vector. See ?contour for the details and examples. I'm sure there is a better way to do this, but when I have data in the format you do: x y z 10, 0.1, 3 10, 0.2, 7 [snip] 10, 1.0, 5 20, 0.1, 12 20, 0.2, 4 I use the following function to convert it to the proper format: image.maker <- function(coords, value){ N <- length(unique(coords[,1])) image.out <- matrix(NA, nrow = N, ncol = N) coords[,1] <- as.numeric(factor(coords[,1])) coords[,2] <- as.numeric(factor(coords[,2])) for (i in 1:nrow(coords)) image.out[coords[i,1], coords[i,2]] <- value[i] return(image.out) } my.image <- image.maker(cv_data[,c("x", "y")], cv_data$z) contour(my.image) HTH, Tyler -- Power corrupts. PowerPoint corrupts absolutely. --Edward Tufte http://www.wired.com/wired/archive/11.09/ppt2.html ______________________________________________ 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.