调整特定 plot 的大小 - Rmarkdown

Question

I have in one chunk a few plots and I want to resize them. I always change the size in the chunk options, like that:

```{r fig1, fig.height = 3, fig.width = 5}
```

But now I want to resize a particular one. I don't want to change the global options. Is there any option to resize particular chart? The reason is that I did a loop and in this loop is there a few charts. For example I want to resize this plot:

  print(ggplot(df_stat, aes(x = value,
                            y=nrow(df_stat))) +
          stat_halfeye()  +
          stat_slab(aes(fill = stat(level)), .width = seq(0.01, 1, by=0.01)) +
          labs(x = i,
               y = NULL) +
          geom_vline(xintercept = 4,
                     colour="red",
                     size=1)+
          theme_classic() +
          theme(axis.text.y = element_blank(),
                axis.ticks.y = element_blank(),
                axis.line.y = element_blank(),
                axis.line.x = element_blank(),
                legend.position="none"))

Answer 1

I think all the plots produced in a chunk will be displayed in the same size frame, but you could change the margins. For example,

library(ggplot2)
for (i in 1:3) {
  print(ggplot(mtcars, aes(cyl, mpg)) + geom_point() +
          theme(plot.margin = unit(c(1,1+i,1,1+i), "cm")))
}

If you're using base graphics, use par(mar =...) to change the margins between plots.

Another way to do it is to save all the plots in a list, then display them in separate chunks, eg

```{r}
library(ggplot2)
result <- list()
for (i in 1:3) {
  result[[i]] <- ggplot(mtcars, aes(cyl, mpg)) + geom_point()
}
```

```{r fig.height=2}
result[[1]]
```

```{r fig.height=3}
result[[2]]
```

```{r fig.height=4}
result[[3]]
```