In LKremer/ggpointdensity: A Cross Between a 2D Density Plot and a Scatter Plot

# devtools::install_github("LKremer/ggpointdensity")

library(tidyverse)
library(viridis)
library(ggpointdensity)
library(patchwork)
theme_set(theme_minimal())

Generate some toy data:

dat <- bind_rows(
  tibble(x = rnorm(7000, sd = 1),
         y = rnorm(7000, sd = 10),
         group = "foo"),
  tibble(x = rnorm(3000, mean = 1, sd = .5),
         y = rnorm(3000, mean = 7, sd = 5),
         group = "bar"))

dat %>%
  ggplot( aes( x = x, y = y, color = group)) +
  geom_point( size = .5)

pp <- dat %>%
  ggplot( aes( x = x, y = y)) +
  geom_point( size = .3) +
  labs(title="geom_point()") + theme(plot.title = element_text(hjust = 0.5))

pd <- dat %>%
  ggplot( aes( x = x, y = y, fill = stat(level))) +
  stat_density_2d(geom = "polygon") +
  scale_fill_viridis() +
  labs(title="stat_density2d(geom='polygon')") + theme(plot.title = element_text(hjust = 0.5))

pb <- dat %>%
  ggplot( aes( x = x, y = y)) +
  geom_bin2d() +
  scale_fill_viridis() +
  labs(title="geom_bin2d()") + theme(plot.title = element_text(hjust = 0.5))

pp + pd + pb

ggsave("/home/lukas/code/ggpointdensity/img/scatter_dens_bin2d.png",
       width = 22, height = 6, units = "cm", dpi = 300)

Use the geom:

dat %>%
  ggplot(aes(x = x, y = y)) +
  geom_pointdensity(size = .3) +
  scale_color_viridis() +
  labs(title="geom_pointdensity()") + theme(plot.title = element_text(hjust = 0.5))

ggsave("/home/lukas/code/ggpointdensity/img/pointdensity.png",
       width = 10, height = 7, units = "cm", dpi = 300)

dat %>%
  ggplot(aes(x = x, y = y)) +
  geom_pointdensity(size = .3) +
  scale_color_viridis() +
  labs(title="geom_pointdensity()") +
  theme_void() +
  theme(plot.title = element_text(hjust = 0.5),
        legend.position = "none")

ggsave("/home/lukas/code/ggpointdensity/img/pointdensity_logo.png",
       width = 7, height = 8, units = "cm", dpi = 300)

The "adjust" argument can be used to adjust the smoothing bandwidth (just as in ggplot2::stat_density):

adj1 <- dat %>%
  ggplot(aes(x = x, y = y)) +
  geom_pointdensity(size = .3, adjust = .1) +
  scale_color_viridis() +
  labs(title="adjust = 0.1") + theme(plot.title = element_text(hjust = 0.5))

adj2 <- dat %>%
  ggplot(aes(x = x, y = y)) +
  geom_pointdensity(size = .3, adjust = 4) +
  scale_color_viridis() +
  labs(title="adjust = 4") + theme(plot.title = element_text(hjust = 0.5))


adj1 + adj2
ggsave("/home/lukas/code/ggpointdensity/img/pointdensity_adj.png",
       width = 18, height = 6, units = "cm", dpi = 300)

Not sure why anyone would do this, but you can use separate bandwidths for x and y:

dat %>%
  ggplot(aes(x = x, y = y)) +
  geom_pointdensity(size = .3, adjust = c(0.1, 2)) +
  scale_color_viridis() +
  labs(title="adjust = c(0.1, 2)") + theme(plot.title = element_text(hjust = 0.5))

ggsave("/home/lukas/code/ggpointdensity/img/pointdensity_xyadj.png",
       width = 10, height = 7, units = "cm", dpi = 300)

Facetting works fine:

dat %>%
  ggplot( aes( x = x, y = y)) +
  geom_pointdensity( size = .25) +
  scale_color_viridis() +
  facet_wrap( ~ group) +
  labs(title="facet_wrap( ~ group)") + theme(plot.title = element_text(hjust = 0.5))

ggsave("/home/lukas/code/ggpointdensity/img/pointdensity_facet.png",
       width = 14, height = 7, units = "cm", dpi = 300)

x- and ylim work as expected:

plim <- dat %>%
  ggplot(aes(x = x, y = y)) +
  geom_pointdensity(size = .5) +
  scale_color_viridis() +
  scale_x_continuous(limits = c(-1, 3)) +
  scale_y_continuous(limits = c(-5, 15)) +
  labs(title="using x- and ylim()") + theme(plot.title = element_text(hjust = 0.5))

coord_cartesian also works:

pcc <- dat %>%
  ggplot(aes(x = x, y = y)) +
  geom_pointdensity(size = .5) +
  scale_color_viridis() +
  coord_cartesian(xlim = c(-1, 3), ylim = c(-5, 15)) +
  labs(title="using coord_cartesian()") + theme(plot.title = element_text(hjust = 0.5))

plim + pcc
ggsave("/home/lukas/code/ggpointdensity/img/pointdensity_zoom.png",
       width = 18, height = 6, units = "cm", dpi = 300)

All functions of geom_point should work too:

dat %>% sample_frac(.1) %>%
  ggplot(aes(x = x, y = y)) +
  geom_pointdensity(size = 3, shape = 17) +
  scale_color_viridis() +
  labs(title="changing shape") + theme(plot.title = element_text(hjust = 0.5))

ggsave("/home/lukas/code/ggpointdensity/img/pointdensity_shape.png",
       width = 10, height = 7, units = "cm", dpi = 300)

dat %>%
  ggplot(aes(x = x, y = y, size = 1/stat(n_neighbors)^1.8)) +
  geom_pointdensity(adjust = .2) +
  scale_color_viridis(option = "inferno", end = .9, direction = -1) +
  scale_size_continuous(range = c(.001, 3))

ggsave("/home/lukas/code/ggpointdensity/img/pointdensity_custom.png",
       width = 14, height = 10, units = "cm", dpi = 300)