Code for ggplot2 implimentation of dog vs cat plot posted by @hpster. using Dev (github) version of ggplot2 and ggalt

dogs_vs_cat_books.R

library("ggplot2")
library("ggalt")
library("dplyr")

color_function <- colorRampPalette(c("cadetblue3", "darkolivegreen3"))

num_books = 35
books <- paste0("book",1:num_books)
dogcat <- runif(length(books), -2.5, 2.5)
dat <- data.frame(books = books, dogcat = dogcat)
dat$books <- factor(books, levels = dat$books[rev(order(dat$dogcat))])
dat <- dat[rev(order(dat$dogcat)),]
dat$fill_color <- color_function(nrow(dat))

ggplot() +
  geom_bar(data = dat, 
           aes(x = books, y = dogcat, fill = (fill_color)), 
           stat = "identity") +
# use second geom_bar is you want the >= 0 side to be a different color, otherwise ignore.           
#  geom_bar(data = dplyr::filter(dat, dogcat >= 0), 
#           aes(x = books, y = dogcat, fill = fill_color), 
#           stat = "identity") +
  coord_flip() +
  theme_bw() +
  scale_y_continuous(breaks = c(-2, -1.5, -1, -0.5, 0, 0.5, 1, 1.5, 2),
                     labels =c ("","1.5x\ncat people","","","Equal","","","","2x\nDog People")) +
  scale_fill_manual(values = rev(dat$fill_color)) +
  labs(title="Books")+
  theme(
    panel.background = element_rect(fill = "gray20"),
    plot.background = element_rect(fill = "gray20"),
    panel.border = element_blank(),
    panel.grid.minor = element_blank(),
    panel.grid.major.y = element_blank(),
    panel.grid.major.x = element_line(colour = "gray80", linetype = "dashed"),
    axis.text = element_text(colour = "gray90"),
    axis.ticks.x = element_line(color = "gray80"),
    axis.ticks.y = element_blank(),
    axis.title = element_blank(),
    plot.title = element_text(color = "gray90", hjust = 0.5),
    legend.position = "none"
    )

ggsave(filename = "dog_vs_cat_books.png", width = 4, height = 6)