Specify height and width of ggplot graph in Rmarkdown knitr output

Question

I have created a plot with ggplot2 where the x-axis labels are not readable unless the plot is larger than default. When viewing in Rstudio I am able to resize dynamically. When saving with ggsave() I am able to specify height and width. How would I do this within the Rmarkdown file so that the output contains a plot of the desired size?

Answer 1

You can specify height and width in the code chunks

```{r, fig.width=10,fig.height=11}
df %>% ggplot(aes(x = x, y = y)) + geom_point()
```

Answer 2

As a side-answer, note that you can also use metric-system units using ggplot2::unit():

library(ggplot2)
knitr::opts_chunk$set(fig.width=unit(18,"cm"), fig.height=unit(11,"cm"))