R-向 PDF 添加页码

Question

我在向 PDF 添加页码时遇到问题。以下是我插入页面/绘图的方式：

pdf( file = pdfFilePath , width = 11 , height = 8.5  )
for ( ... ) {
    grid.newpage()
    pushViewport( viewport( layout = grid.layout( 2 , 2 ) ) )
    ... print 4 plots ....
}

onefile 似乎按页码命名文件，但我希望页码出现在同一个文件中。

编辑
我修改了 @Gavin 的代码示例以生成混合图形类型的工作版本以获取页码：

require(ggplot2)
pdf( file = "FILE_PATH_TO_SAVE_PDF_HERE" , width = 11 , height = 8.5  )
par( oma = c ( 4 , 4 , 4 , 4 ) , mar=c( 4 , 0 , 2 , 0 )  )
plot( 0:11 , type = "n", xaxt="n", yaxt="n", bty="n", xlab = "", ylab = ""  )
mtext( side = 3 , line = 0 , outer = TRUE  , cex = 1.5 , family="mono" , "Title" )
grid.newpage()
p1 <- ggplot(data.frame(X = 1:10, Y = runif(10)), aes(x = X, y = Y)) + 
        geom_point()
vplayout <- function(x, y) {
    viewport(layout.pos.row = x, layout.pos.col = y)
}
pushViewport(viewport(layout = grid.layout(2, 2)))
print(p1, vp = vplayout(1,1))
print(p1, vp = vplayout(1,2))
print(p1, vp = vplayout(2,1))
print(p1, vp = vplayout(2,2))
mtext( "1" , side = 1 , line = 3 , outer = TRUE , cex = .8 , family="mono"  )
dev.off()

Answer 1

从我对 Q 的第二条评论中，我建议使用 mtext() 进行基本图形解决方案。这似乎适用于OP，所以我在这里显示一个扩展版本：

基本图形：

op <- par(oma = c(2,0,0,0))
layout(matrix(1:4, ncol = 2))
plot(1:10)
plot(1:10)
plot(1:10)
plot(1:10)
mtext(side = 1, text = "Page 1", outer = TRUE)
layout(1)
par(op)

结果：

@SFun28 报告这个想法也适用于他的 ggplot/grid 图形，但不适合我。运行下面代码块的最后一行后，我收到以下错误：

> mtext(side = 1, text = "Page 1")
Error in mtext(side = 1, text = "Page 1") : 
  plot.new has not been called yet

这表明警告不要混合基础图形和网格图形。

require(ggplot2)
p1 <- ggplot(data.frame(X = 1:10, Y = runif(10)), aes(x = X, y = Y)) + 
        geom_point()
vplayout <- function(x, y) {
    viewport(layout.pos.row = x, layout.pos.col = y)
}
grid.newpage()
pushViewport(viewport(layout = grid.layout(2, 2)))
print(p1, vp = vplayout(1,1))
print(p1, vp = vplayout(1,2))
print(p1, vp = vplayout(2,1))
print(p1, vp = vplayout(2,2))
mtext(side = 1, text = "Page 1")

Answer 2

我修改了 Paul Murrell 的 示例 < a href="http://www.stat.auckland.ac.nz/~paul/RGraphics/rgraphics.html" rel="nofollow noreferrer">R 图形 书绘制了整个使用网格进行绘图，然后将标签放置在单独视口的底部。我将微调留给OP，因为我不知道各个图在做什么，但是在绘制标签的设备底部创建一个额外的视口（？）的总体思路应该映射到 < code>grid.layout() 想法已被 @SFun28 使用：

label <- textGrob("A page number! ",
                  x=0.5, y = 1.0, just="centre")
x <- seq(0.1, 0.9, length=50)
y <- runif(50, 0.1, 0.9)
gplot <- 
  gTree(
    children=gList(rectGrob(gp=gpar(col="grey60",
                                    fill="white")),
                   linesGrob(x, y), 
                   pointsGrob(x, y, pch=16, 
                              size=unit(1.5, "mm"))),
    vp=viewport(width=unit(1, "npc") - unit(5, "mm"), 
                height=unit(1, "npc") - unit(10, "mm")))



layout <- grid.layout(2, 1,
                      widths=unit(c(1, 1), 
                                  c("null", "grobwidth"),
                                  list(NULL, label)),
                      heights = unit(c(1, 1),
                                     c("null", "grobheight"),
                                     list(NULL, label)))

grid.rect(gp=gpar(col="grey60", fill="grey90"))
pushViewport(viewport(layout=layout))
pushViewport(viewport(layout.pos.row=2))
grid.draw(label)
popViewport()
pushViewport(viewport(layout.pos.col=1))
grid.draw(gplot)
popViewport(2)

给出：

Answer 3

library(ggplot2)
plots = replicate(8, qplot(1,1))
library(gridExtra)
p <- 
do.call(marrangeGrob, c(plots, list(ncol=2, nrow=2, top =NULL, 
        bottom = quote(quote(paste(g, "/",pages))))))

p

ggsave("multipage.pdf", p)

（需要 quote(quote()) 来维持惰性求值，以某种方式）

Answer 4

正如@Gavin提到的，我在将ggplot与mtext混合时也遇到了错误。

这是使用 ggplot 时对我来说非常有效的方法：

require(ggplot2)
require(grid)
printWithFooter = function(gg_obj, bottom_left = NULL, bottom_right = NULL) 
{
  print(gg_obj)
  if (!is.null(bottom_right))
  {
    label = textGrob(bottom_right,
                     x = 0.98,  # right side
                     y = 0.0,   # bottom
                     just="right", 
                     hjust = NULL,
                     vjust = -.5,
                     gp=gpar(fontsize=7, col="#333333"))
    grid.draw(label)
  }
  if (!is.null(bottom_left))
  {
    label = textGrob(bottom_left,
                     x = 0.02,  # left side
                     y = 0.0,   # bottom
                     just="left", 
                     hjust = NULL,
                     vjust = -.5,
                     gp=gpar(fontsize=7, col="#333333"))  
    grid.draw(label)
  }
}

## example

d = data.frame(x = runif(1:20), y = runif(1:20), facet = rep(1:4, each=5))
p = ggplot(d) + geom_point(aes(x=x, y=y)) + facet_wrap(~facet)
printWithFooter(p, "left", "right")