R/multiplot.R

In tranlm/lrecCompare: Comparative methods in the estimation of a treatment specific mean outcome

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# Description: Add comment
#
# Author: Linh Tran <tranlm@berkeley.edu>
# Date: Jun 18, 2015
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#' @export
multiplot <- function(..., plotlist=NULL, file, cols=1, layout=NULL) {
	require(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))
		}
	}
}