How to render a gganimate graph in html using rmarkdown::render(), without generating unwanted output

Question

I am trying to render gganimate() plots in html using an r-markdown document. I am able to create the html document (though the simple example below takes at least a minute) and the gganimate graphic successfully loads in the browser (firefox), however, I get a bunch of unwanted output in the browser.

The unwanted output looks like this:

---

Frame 1 (1%)

Frame 2 (2%)

Frame 3 (3%)

...

Frame 96 (96%)

Frame 97 (97%)

Frame 98 (98%)

Frame 99 (99%)

Frame 100 (100%)

Finalizing encoding... done!

---

Like I said, after this unwanted output, the animation is indeed displayed correctly.

I have tried messing around with the knitR code-chunk heading options. Mostly been looking at these options here: https://bookdown.org/yihui/rmarkdown/r-code.html

I have also tried the solutions suggested on this post: suppress console output in r markdown, but keep plot Specifically, I have tried wrapping the ggplot object in "invisible".

Just copy the code below into an Rmarkdown document, save this Rmarkdown document as "example.Rmd", then, in the R console run: rmarkdown::render("example.Rmd")

---
    title: "Testing gganimate with R Markdown"
    output: html_document
---

```{r message = FALSE}
library(ggplot2)
library(gganimate)
ggplot(mtcars, aes(factor(cyl), mpg)) + 
  geom_boxplot() + 
  # Here comes the gganimate code
  transition_states(
    gear,
    transition_length = 2,
    state_length = 1
  ) +
  enter_fade() + 
  exit_shrink() +
  ease_aes('sine-in-out')
```

Answer 1

One workaround for this is to assign the animation to an object goo <- ggplot(... and write the animation to a file anim_save("goo.gif", goo) while suppressing results from the code chunk results = FALSE. Then render the gif in markdown immediately after the code chunk ![](goo.gif).

E.g.

---
title: "Testing gganimate with R Markdown"
output: html_document
---


```{r message = FALSE, warning = FALSE, results = FALSE}
library(ggplot2)
library(gganimate)
goo <- ggplot(mtcars, aes(factor(cyl), mpg)) + 
  geom_boxplot() + 
  # Here comes the gganimate code
  transition_states(
    gear,
    transition_length = 2,
    state_length = 1
  ) +
  enter_fade() + 
  exit_shrink() +
  ease_aes('sine-in-out')

anim_save("goo.gif", goo)
```


![](goo.gif)