Adding lines in ggplot2
Dear Eduardo, This a solution that you seem to want n <- 1:10 x <- sqrt(n) y <- log(n) qplot(n, x, geom="line", colour="darkgreen") + geom_line(data = data.frame(n , x = y), colour="red") But please compare it with the solution (code + result) below. Formatting the data.frame might be a bit more work, but formatting your graph is much easier. n <- 1:10 dataset <- rbind( data.frame(Number = n, Function = "sqrt", Result = sqrt(n)), data.frame(Number = n, Function = "log", Result = log(n)) ) #Using the default colours ggplot(dataset, aes(x = Number, y = Result, colour = Function)) + geom_line() #Using user-specified colours ggplot(dataset, aes(x = Number, y = Result, colour = Function)) + geom_line() + scale_colour_manual(values = c(sqrt = "darkgreen", log = "red")) Think about the gain when you want to display much more than 2 lines... dataset <- expand.grid(Number = n, Power = seq(0, 2, length = 21)) dataset$Result <- dataset$Number ^ dataset$Power ggplot(dataset, aes(x = Number, y = Result, colour = factor(Power))) + geom_line() HTH, Thierry ------------------------------------------------------------------------ ---- ir. Thierry Onkelinx Instituut voor natuur- en bosonderzoek team Biometrie & Kwaliteitszorg Gaverstraat 4 9500 Geraardsbergen Belgium Research Institute for Nature and Forest team Biometrics & Quality Assurance Gaverstraat 4 9500 Geraardsbergen Belgium tel. + 32 54/436 185 Thierry.Onkelinx at inbo.be www.inbo.be To call in the statistician after the experiment is done may be no more than asking him to perform a post-mortem examination: he may be able to say what the experiment died of. ~ Sir Ronald Aylmer Fisher The plural of anecdote is not data. ~ Roger Brinner The combination of some data and an aching desire for an answer does not ensure that a reasonable answer can be extracted from a given body of data. ~ John Tukey
-----Oorspronkelijk bericht----- Van: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] Namens Eduardo de Oliveira Horta Verzonden: woensdag 5 januari 2011 3:56 Aan: r-help Onderwerp: [R] Adding lines in ggplot2 Hello, this is probably a recurrent question, but I couldn't find any answers that didn't involve the expression "data frame"... so perhaps I'm looking for something new here. I wanted to find a code equivalent to
x=sqrt(1:10) y=log(1:10) plot(1:10, x, type="lines", col="darkgreen") lines(1:10, y,
col="red") to use with ggplot2. I've tried
x=sqrt(1:10)
y=log(1:10)
qplot(1:10, x, geom="line", colour=I("darkgreen"))
geom_line(1:10, y,
colour="red")
Error: ggplot2 doesn't know how to deal with data of class numeric but it seems that the "data frame restriction" is really very restrictive here. Any solutions that don't imply using as.data.frame to my data? Thanks in advance, and best regards! Eduardo Horta [[alternative HTML version deleted]]
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