Error: The animation object does not specify a save_animation method

Question

Im trying to create a bar chart race with R following the method delow. While all the pngs are created when I try to save them as a gif file thenI get:

Error: The animation object does not specify a save_animation method

Does it happen because I create multiple files?

#This script contains a function to produce a "bar chart race" in R

#The following links were invaluable:
#https://www.blakeshaffer.ca/post/making-animated-charts-with-gganimate/
#https://stackoverflow.com/questions/52623722/how-does-gganimate-order-an-ordered-bar-time-series


#load required packages:
library(tidyverse)
library(gganimate)


#inputs:
#data - the dataset, must contain a column called "year"
#x - the column which contains the numeric value to plot 
#y - the column which contains the labels of the plot

#optional: 
#title - title to show at the top of the graph, defaults to blank
#caption - text show in footer, defaults to blank
#number - filter to top "number" defaults to 10 for top 10 in each period
#parameters passed to "animate" function: defaults to nframes=300, fps=5, end_pause=20

make_barchart_race <- function(data,x,y,
                               number=10,
                               title="",
                               caption="",
                               nframes=300,
                               fps=5,
                               end_pause=20){
  #set up variables for use with tidy evaluation
  y <- rlang::enquo(y)
  x <- rlang::enquo(x)
  number <- rlang::enquo(number)

  #take the input dataset, compute ranks within each time period
  data %>%
    group_by(year) %>%
    arrange(-!!y) %>%
    mutate(rank=row_number()) %>%
    #filter to top "number"
    filter(rank<=!!number) -> data

  #plot the data
  data %>%
    ggplot(aes(x=-rank,y=!!y,fill=!!x, group=!!x)) +
    geom_tile(aes(y=!!y/2,height=!!y),width=0.9,show.legend = F)+
    geom_text(aes(label=!!x),
              hjust="right",
              colour="black",
              fontface="bold",
              nudge_y=-1000)+
    geom_text(aes(label=scales::comma(!!y)),
              hjust="left",
              nudge_y=2000,
              colour="grey30")+
    theme_minimal() +
    coord_flip(clip="off") +
    scale_x_discrete("") +
    scale_y_continuous("",labels=scales::comma)+
    theme(panel.grid.major.y=element_blank(),
          panel.grid.minor.x=element_blank(),
          plot.title= element_text(size=20,colour="grey50",face="bold"),
          plot.caption = element_text(colour="grey50"),
          plot.subtitle = element_text(size=20,colour="grey50",face="bold"),
          plot.margin = margin(1,1,1,2,"cm"),
          axis.text.y=element_blank())+
    #this bit does the animation by year
    transition_time(year) +
    labs(title=title,
         subtitle='{round(frame_time,0)}',
         caption=caption)-> p

  #animate the plot - this is returned by the function
  animate(p, nframes = nframes, fps = fps, end_pause = end_pause)
}



#Example usage:

#read in a dataset:
data <- read_csv('https://gist.githubusercontent.com/johnburnmurdoch/2e5712cce1e2a9407bf081a952b85bac/raw/08cf82f5e03c619f7da2700d1777da0b5247df18/INTERBRAND_brand_values_2000_2018_decimalised.csv')

#call the function to make the animation:
g<-make_barchart_race(data,
                   name,
                   value,
                   title="Interbrand Top Global Brands\n(brand values in $)",
                   caption="Source: Interbrand")
#save it:
print(g) # print first
anim_save("out.gif",animation = g)

Answer 1

I had the same problem with my animation. This solved it for me: https://www.bountysource.com/

You add renterer = gifski_renderer() to the making of the animation like so:

library(gifski)
library(png)    
animate(myPlot, duration = 5, fps = 20, width = 200, height = 200, renderer = gifski_renderer())

Then I had no problem saving the animation like you tried with anim_save("out.gif",animation = g)

Answer 2

I had to return the plot object, and call animate on the plot object with gifski_renderer() to make it work, below's a reproducible example:

make_barchart_race <- function(data,x,y,
                               number=10,
                               title="",
                               caption=""){
  #set up variables for use with tidy evaluation
  y <- rlang::enquo(y)
  x <- rlang::enquo(x)
  number <- rlang::enquo(number)

  #take the input dataset, compute ranks within each time period
  data %>%
    group_by(year) %>%
    arrange(-!!y) %>%
    mutate(rank=row_number()) %>%
    #filter to top "number"
    filter(rank<=!!number) -> data

  #plot the data
  data %>%
    ggplot(aes(x=-rank,y=!!y,fill=!!x, group=!!x)) +
    geom_tile(aes(y=!!y/2,height=!!y),width=0.9,show.legend = F)+
    geom_text(aes(label=!!x),
              hjust="right",
              colour="black",
              fontface="bold",
              nudge_y=-1000)+
    geom_text(aes(label=scales::comma(!!y)),
              hjust="left",
              nudge_y=2000,
              colour="grey30")+
    theme_minimal() +
    coord_flip(clip="off") +
    scale_x_discrete("") +
    scale_y_continuous("",labels=scales::comma)+
    theme(panel.grid.major.y=element_blank(),
          panel.grid.minor.x=element_blank(),
          plot.title= element_text(size=20,colour="grey50",face="bold"),
          plot.caption = element_text(colour="grey50"),
          plot.subtitle = element_text(size=20,colour="grey50",face="bold"),
          plot.margin = margin(1,1,1,2,"cm"),
          axis.text.y=element_blank())+
    #this bit does the animation by year
    transition_time(year) +
    labs(title=title,
         subtitle='{round(frame_time,0)}',
         caption=caption)-> p
return(p)
}
#call the function to make the animation:
g<-make_barchart_race(data,
                   name,
                   value,
                   title="Interbrand Top Global Brands\n(brand values in $)",
                   caption="Source: Interbrand")

animate(g, nframes = 300, fps = 5, end_pause = 20,renderer=gifski_renderer("test.gif"))