gganimate "Error in order(ind) : argument 1 is not a vector"

Question

I am trying to animate a map of performance over time using the gganimate package. I am able to animate other ggplots that use geom_point() but this one is throwing an error I cannot figure out.

I have made a workable example below that throws the same error:

library(tidyr)
library(ggplot2)
library(gganimate)
library(maps)
library(mapproj)
library(evaluate)

map <- map_data("world")
colnames(map)[1] <- "x"
colnames(map)[2] <- "y"

A1 <- data.frame(OrganisationID=c(1:10),x=rnorm(10) * 2 + 13,y= rnorm(10) + 48,`01 Jan 2020`=runif(10),"02 Jan 2020"=runif(10),
                 "03 Jan 2020"=runif(10),"04 Jan 2020"=runif(10),"05 Jan 2020"=runif(10),
                 "06 Jan 2020"=runif(10),"07 Jan 2020"=runif(10))
A1 <- gather(A1, Date, Performance, `X01.Jan.2020`:`X07.Jan.2020`, factor_key=TRUE)
A1$Date <- as.Date(A1$Date, format = "X%d.%b.%Y")
A1$Size <- sample(500:1000,70,T)


longitude_lim = sort(c(max(A1$x), min(A1$x)))
latitude_lim = sort(c(max(A1$y), min(A1$y)))

base_map <- ggplot() +
  geom_polygon(data = map, aes(x=x, y = y, group = group), fill="grey", alpha=0.3) +
  coord_fixed(xlim = longitude_lim, ylim = latitude_lim) +
  labs(title = "Performance Regional") +
  theme_bw() +
  geom_point(aes(x=A1$x, y=A1$y, color=A1$Performance), alpha=0.9) +
  scale_colour_gradient2(
    low = "red",
    mid = "#ffffcc",
    high = "#33cc33",
    midpoint = 0.85 
  )

# combine previous map lists, add points to map and animate
base_map
anim <- base_map +
  transition_states(A1$Date, transition_length = 2,
                    state_length = 1)
anim 

As you can see the base plot renders fine, but when I try to animate it I get

Error in order(ind) : argument 1 is not a vector

I don't know where to start untangling this as I do not have an object called 'ind' so I assume it's some process inside gganimate. Any hints and tips are appreciated (also on a more efficient way to create my RepRoX)!

Answer 1

The issue is that you use two datasets, map and A1. To make your code work you have to "tell" gganimate which dataset to use for the animation by e.g. making A1 the global dataset by passing it to ggplot().

BTW: And as general rule when using ggplot2 don't assign variables to aesthetics via A1$...:

base_map <- ggplot(data = A1) +
  geom_polygon(aes(x=x, y = y, group = group), data = map, fill="grey", alpha=0.3) +
  coord_fixed(xlim = longitude_lim, ylim = latitude_lim) +
  labs(title = "Performance Regional") +
  theme_bw() +
  geom_point(aes(x=x, y=y, color=Performance), alpha=0.9) +
  scale_colour_gradient2(
    low = "red",
    mid = "#ffffcc",
    high = "#33cc33",
    midpoint = 0.85 
  )

# combine previous map lists, add points to map and animate
base_map
anim <- base_map +
  transition_states(Date, transition_length = 2,
                    state_length = 1)
anim