Hi, The function "ggplot" does plot and return a plot. For example, we can write:
y = ggplot(.. .....) Then y is a plot. How can we modify the multiplot function so that it can also return a plot? Multiplot.R is here: http://www.cookbook-r.com/Graphs/Multiple_graphs_on_one_page_(ggplot2)/, and the code is as below. Any advice on returning a multi-ggplot would help! Thanks, Miao # Multiple plot function # # ggplot objects can be passed in ..., or to plotlist (as a list of ggplot objects) # - cols: Number of columns in layout # - layout: A matrix specifying the layout. If present, 'cols' is ignored. # # If the layout is something like matrix(c(1,2,3,3), nrow=2, byrow=TRUE), # then plot 1 will go in the upper left, 2 will go in the upper right, and # 3 will go all the way across the bottom. # multiplot <- function(..., plotlist=NULL, file, cols=1, layout=NULL) { library(grid) # Make a list from the ... arguments and plotlist plots <- c(list(...), plotlist) numPlots = length(plots) # If layout is NULL, then use 'cols' to determine layout if (is.null(layout)) { # Make the panel # ncol: Number of columns of plots # nrow: Number of rows needed, calculated from # of cols layout <- matrix(seq(1, cols * ceiling(numPlots/cols)), ncol = cols, nrow = ceiling(numPlots/cols)) } if (numPlots==1) { print(plots[[1]]) } else { # Set up the page grid.newpage() pushViewport(viewport(layout = grid.layout(nrow(layout), ncol(layout)))) # Make each plot, in the correct location for (i in 1:numPlots) { # Get the i,j matrix positions of the regions that contain this subplot matchidx <- as.data.frame(which(layout == i, arr.ind = TRUE)) print(plots[[i]], vp = viewport(layout.pos.row = matchidx$row, layout.pos.col = matchidx$col)) } } } [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.