Overlapped grobs generated by arrangeGrob when view from RStudio and knit to PDF

Question

I'm using RStudio under windows 10. I want to generate a PDF report. Below is a sample code showing the problem.

library(ggplot2)
library(grid)
library(gridExtra)
x <- data.frame(x=c(1:100), y=c(1:100))
x_t1 <- data.frame(a = 1, b = 1)
x_t2 <- data.frame(a = 2, b = 2)
x_t3 <- data.frame(a = 3, b = 3)
x_grobs <- list(
  textGrob("text 1"),
  textGrob("text 2"),
  tableGrob(x_t1),
  textGrob("text 4"),
  tableGrob(x_t2),
  textGrob("text 6"),
  tableGrob(x_t3),
  ggplotGrob(ggplot(x, aes(x, y))+geom_point())
)
x_heights <- c(rep(1, 7), 14)
x_arrgorb <- arrangeGrob(grobs=x_grobs,
                         ncol = 1,
                         heights = x_heights)
grid.newpage()
grid.draw(x_arrgorb)

The output view from my computer is like below:

You can see that though grobs are arranged in sequence and heights as expected, they are heavily overlapped. When I knit it to an A4 size PDF, the result is similar. All grobs squeezed on the top half of the page, leave most spaces empty:

I tried to set the viewport but did not end up with difference. I think it seems to be related to the plotting area, which has a fixed size, and all grobs are squeezed to fit in this plotting area. I don't know how to adjust this, or if this is the root cause. Please advise. Thank you.

Answer 1

To change the figure size so there is room for the plot when rendering to PDF, use the chunk options for your plotting code chunk and change fig.height and fig.width:

```{r chunkname, fig.height=10, fig.width=8}
<plotting_code>
```

Answer 2

The issue appears to be with the definition of the x_heights. The first two grob are text and should have height 1 and then the first tableGrob is plotted with height 2. Edit the x_heights as

x_heights <- c(1, 1, 2, 1, 2, 1, 2, 14)

The resulting plot I get is: