It turned out that rearranging the data was indeed the key to get the image I want. The way I do it now is this:
tt <- read.csv(file="file.csv", header=T, sep=",", dec=".", stringsAsFactors=F) names(tt) <- c('time','abs') dat <- with(tt, table(time, abs)) image(dat,col=rainbow(256)) I'm now modifying the rainbow color palette to match my needs. Also, the X-axis and Y-axis display values between 0 and 1, so I want to change them to show the actual time and abs values. -- View this message in context: http://r.789695.n4.nabble.com/re-arranging-data-to-create-an-image-or-heatmap-tp3327986p3339498.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.