options of ggplot2: fixing range and colors

00ggplot2_options.R

library(ggplot2)
library(animation)
library(dplyr)

set.seed(100)
data <- data.frame(value = rnorm(1000, mean = 5, sd = sqrt(5)))

### continuous-scale axis ###

# BAD EXAMPLE: Ranges are changing too fast...

saveGIF({
  for (i in 1:nrow(data)) {
    p <- ggplot(slice(data, 1:i), aes(x = value)) + geom_bar()
    
    print(p)
  }
}, movie.name = "animation_bad1.gif", interval=c(rep(0.02, nrow(data) - 1), 5) )


# GOOD EXAMPLE: specify `limits` and `binwidth`

xlimits <- range(data)
xrangewidth <- diff(limits)
ylimits <- c(0,100)

saveGIF({
  for (i in 1:nrow(data)) {
    p <- ggplot(slice(data, 1:i), aes(x = value)) + geom_bar(binwidth = xrangewidth/30) +
      scale_x_continuous(limits = xlimits) +
      scale_y_continuous(limits = ylimits)
    
    print(p)
  }
}, movie.name = "animation1.gif", interval=c(rep(0.02, nrow(data) - 1), 5) )

# But, when you use scale_*_log10, limit must be larger than 0, from the definition of logarithm.

ylimits_for_log <- c(1,100)

saveGIF({
  for (i in 1:nrow(data)) {
    p <- ggplot(slice(data, 1:i), aes(x = value)) + geom_bar(binwidth = xrangewidth/30) +
      scale_x_continuous(limits = xlimits) +
      scale_y_log10(limits = ylimits_for_log)
    
    print(p)
  }
}, interval=c(rep(0.02, nrow(data) - 1), 5) )


#### discrete-scale axis ####

breaks <- floor(limits[1]):ceiling(limits[2])
labels <- sapply(1:(length(breaks)-1), function(i) paste(breaks[i], "~", breaks[i+1]))
data %>%
  mutate(valuerange = cut(value,
                          breaks = breaks,
                          labels = labels)
         ) -> data2

ylimits <- c(0, max(table(data2$valuerange)))


# BAD EXAMPLE:
# you cannot use `scale_x_continuous()` since x is categorical value.
saveGIF({
  for (i in 1:nrow(data)) {
    p <- ggplot(slice(data2, 1:i), aes(x = valuerange)) + geom_bar() +
      scale_y_continuous(limits = ylimits)
    
    print(p)
  }
}, movie.name = "animation_bad2.gif", interval=c(rep(0.02, nrow(data) - 1), 5) )

# GOOD EXAMPLE: use `drop = FALSE`
saveGIF({
  for (i in 1:nrow(data)) {
    p <- ggplot(slice(data2, 1:i), aes(x = valuerange)) + geom_bar() +
      scale_x_discrete(drop = FALSE) +
      scale_y_continuous(limits = ylimits)
    
    print(p)
  }
}, movie.name = "animation2.gif", interval=c(rep(0.02, nrow(data) - 1), 5) )

# You can specify order by `limits` option
saveGIF({
  for (i in 1:nrow(data)) {
    p <- ggplot(slice(data2, 1:i), aes(x = valuerange)) + geom_bar() +
      scale_x_discrete(drop = FALSE, limits = rev(labels)) +
      scale_y_continuous(limits = ylimits)
    
    print(p)
  }
}, interval=c(rep(0.02, nrow(data) - 1), 5) )

#### colour and fill ####
# BAD EXAMPLE: color arrangement is changing like Chameleon...
saveGIF({
  for (i in 1:nrow(data)) {
    p <- ggplot(slice(data2, 1:i), aes(x = valuerange, fill = valuerange)) + geom_bar() +
      scale_x_discrete(drop = FALSE) +
      scale_y_continuous(limits = ylimits) +
    
    print(p)
  }
}, movie.name = "animation_bad3.gif", interval=c(rep(0.02, nrow(data) - 1), 5) )

# GOOD EXAMPLE: use `scale_fill_discrete()`
# (For colour, use `scale_colour_discrete()` instead)
saveGIF({
  for (i in 1:nrow(data)) {
    p <- ggplot(slice(data2, 1:i), aes(x = valuerange, fill = valuerange)) + geom_bar() +
      scale_x_discrete(drop = FALSE) +
      scale_y_continuous(limits = ylimits) +
      scale_fill_discrete(drop = FALSE)
    
    print(p)
  }
}, movie.name = "animation3.gif", interval=c(rep(0.02, nrow(data) - 1), 5) )