如何在R中保存网格图？

Question

我有一个网格图对象g.

class(g)
"gtable" "grob"   "gDesc" 

我可以使用grid.draw(g)绘制情节.但是,我无法找到将绘图保存为pdf文件的方法.

我试过了:

ggsave(g, file="plot.png")

但显然ggsave不适用于这样的对象.

以下是？grid.draw帮助页面中的示例:

grid.newpage()
## Create a graphical object, but don't draw it
l <- linesGrob()
## Draw it
grid.draw(l)

绘图效果很好,但保存/打印会导致问题.

对此有任何解决方法吗？谢谢!

Answer 1

这就是MrFlick回答的问题,但对于PDF(你在问题中提出的要求).

## Initiate writing to PDF file
pdf("path/to/file/PDFofG.pdf", height = 11, width = 8.5, paper = "letter")

## Create a graphical object g here
g # print it

## Stop writing to the PDF file
dev.off()

Answer 2

值得添加的是,更新ggsave版本可以实现所需的导出.

包

# Load
lapply(c("ggplot2",
         "gridExtra"), 
       require, 
       character.only = TRUE)
sessionInfo()

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] gridExtra_2.2.1 ggplot2_2.1.0  

loaded via a namespace (and not attached):
[1] colorspace_1.2-6 grid_3.1.1       gtable_0.2.0     munsell_0.4.3    plyr_1.8.3       Rcpp_0.12.6     
[7] scales_0.4.0     tools_3.1.1  

图表准备和导出

a  <- ggplot(data = mtcars) +
  geom_point(aes(x = mpg, y = cyl))

b  <- ggplot(data = mtcars) +
  geom_line(aes(x = wt, y = vs))

# grid
gridAB  <- grid.arrange(a, b)
# Export
ggsave(filename="ab.pdf", plot=gridAB)

类

> class(gridAB)
[1] "gtable" "gTree"  "grob"   "gDesc" 

预习