基于对上面巴蒂斯特评论的成熟考虑(即我基本上捏了他所有的代码),我整理了一个简单的例子。显然,您需要尝试绘图的格式和大小,并且textGrob
需要在其他地方定义和格式化,但这些都是细节。生成的图如下,代码如下。其中大部分由函数定义占用,底部有绘图代码。
gtable_arrange <- function(..., grobs=list(), as.table=TRUE,
top = NULL, bottom = NULL,
left = NULL, right = NULL, draw=TRUE){
require(gtable)
# alias
gtable_add_grobs <- gtable_add_grob
dots <- list(...)
params <- c("nrow", "ncol", "widths", "heights",
"respect", "just", "z") # TODO currently ignored
layout.call <- intersect(names(dots), params)
params.layout <- dots[layout.call]
if(is.null(names(dots)))
not.grobnames <- FALSE else
not.grobnames <- names(dots) %in% layout.call
if(!length(grobs))
grobs <- dots[! not.grobnames ]
## figure out the layout
n <- length(grobs)
nm <- n2mfrow(n)
if(is.null(params.layout$nrow) & is.null(params.layout$ncol))
{
params.layout$nrow = nm[1]
params.layout$ncol = nm[2]
}
if(is.null(params.layout$nrow))
params.layout$nrow = ceiling(n/params.layout$ncol)
if(is.null(params.layout$ncol))
params.layout$ncol = ceiling(n/params.layout$nrow)
if(is.null(params.layout$widths))
params.layout$widths <- unit(rep(1, params.layout$ncol), "null")
if(is.null(params.layout$heights))
params.layout$heights <- unit(rep(1,params.layout$nrow), "null")
positions <- expand.grid(row = seq_len(params.layout$nrow),
col = seq_len(params.layout$ncol))
if(as.table) # fill table by rows
positions <- positions[order(positions$row),]
positions <- positions[seq_along(grobs), ] # n might be < ncol*nrow
## build the gtable, similar steps to gtable_matrix
gt <- gtable(name="table")
gt <- gtable_add_cols(gt, params.layout$widths)
gt <- gtable_add_rows(gt, params.layout$heights)
gt <- gtable_add_grobs(gt, grobs, t = positions$row,
l = positions$col)
## titles given as strings are converted to text grobs
if (is.character(top))
top <- textGrob(top)
if (is.character(bottom))
bottom <- textGrob(bottom)
if (is.character(right))
right <- textGrob(right, rot = -90)
if (is.character(left))
left <- textGrob(left, rot = 90)
if(!is.null(top)){
gt <- gtable_add_rows(gt, heights=grobHeight(top), 0)
gt <- gtable_add_grobs(gt, top, t=1, l=1, r=ncol(gt))
}
if(!is.null(bottom)){
gt <- gtable_add_rows(gt, heights=grobHeight(bottom), -1)
gt <- gtable_add_grobs(gt, bottom, t=nrow(gt), l=1, r=ncol(gt))
}
if(!is.null(left)){
gt <- gtable_add_cols(gt, widths=grobWidth(left), 0)
gt <- gtable_add_grobs(gt, left, t=1, b=nrow(gt), l=1, r=1)
}
if(!is.null(right)){
gt <- gtable_add_cols(gt, widths=grobWidth(right), -1)
gt <- gtable_add_grobs(gt, right, t=1, b=nrow(gt), l=ncol(gt), r=ncol(gt))
}
if(draw){
grid.newpage()
grid.draw(gt)
}
gt
}
# load needed libraries
library(ggplot2)
# Set loop counter and create list to store objects
imax=37
plist <- list()
p <- ggplot(mtcars, aes(x = wt, y = mpg)) + geom_line()
for(i in 1:imax){
plist[[i]] <- p + ggtitle(i)
}
# build list of grobs
grob.list <- lapply(plist, ggplotGrob)
# prepare titles
title.main <- textGrob("Main title")
title.sub <- textGrob("Subtitle")
# then arrange as required
g <- gtable_arrange(ncol=6, grobs=grob.list,
top=title.main, bottom=title.sub, draw=FALSE)
ann <- grobTree(rectGrob(), textGrob("Annotation box here"))
g <- gtable_add_grobs(g, ann, t=nrow(g)-1, l=2, r=ncol(g))
# save it all together
png(file = "out.png",width=1000, height=710, units = "px")
grid.draw(g)
dev.off()