ggplot - Multiple legends arrangement

The idea is to create each plot individually (color, fill & size) then extract their legends and combine them in a desired way together with the main plot.

See more about the cowplot package here & the patchwork package here

library(ggplot2)library(cowplot)   # get_legend() & plot_grid() functionslibrary(patchwork) # blank plot: plot_spacer()data <- seq(1000, 4000, by = 1000)colorScales <- c("#c43b3b", "#80c43b", "#3bc4c4", "#7f3bc4")names(colorScales) <- data# Original plot without legendp0 <- ggplot() +  geom_point(aes(x = data, y = data,                  color = as.character(data), fill = data, size = data),             shape = 21  ) +  scale_color_manual(    name = "Legend 1",    values = colorScales  ) +  scale_fill_gradientn(    name = "Legend 2",    limits = c(0, max(data)),    colours = rev(c("#000000", "#FFFFFF", "#BA0000")),    values = c(0, 0.5, 1)  ) +  scale_size_continuous(name = "Legend 3") +  theme(legend.direction = "vertical", legend.box = "horizontal") +  theme(legend.position = "none")# color onlyp1 <- ggplot() +  geom_point(aes(x = data, y = data, color = as.character(data)),             shape = 21  ) +  scale_color_manual(    name = "Legend 1",    values = colorScales  ) +  theme(legend.direction = "vertical", legend.box = "vertical")# fill onlyp2 <- ggplot() +  geom_point(aes(x = data, y = data, fill = data),             shape = 21  ) +  scale_fill_gradientn(    name = "Legend 2",    limits = c(0, max(data)),    colours = rev(c("#000000", "#FFFFFF", "#BA0000")),    values = c(0, 0.5, 1)  ) +  theme(legend.direction = "vertical", legend.box = "vertical")# size onlyp3 <- ggplot() +  geom_point(aes(x = data, y = data, size = data),             shape = 21  ) +  scale_size_continuous(name = "Legend 3") +  theme(legend.direction = "vertical", legend.box = "vertical")

Get all legends

leg1 <- get_legend(p1)leg2 <- get_legend(p2)leg3 <- get_legend(p3)# create a blank plot for legend alignment blank_p <- plot_spacer() + theme_void()

Combine legends

# combine legend 1 & 2leg12 <- plot_grid(leg1, leg2,                   blank_p,                   nrow = 3)# combine legend 3 & blank plotleg30 <- plot_grid(leg3, blank_p,                   blank_p,                    nrow = 3)# combine all legendsleg123 <- plot_grid(leg12, leg30,                    ncol = 2)

Put everything together

final_p <- plot_grid(p0,                     leg123,                     nrow = 1,                     align = "h",                     axis = "t",                     rel_widths = c(1, 0.3))print(final_p)

Created on 2018-08-28 by the reprex package (v0.2.0.9000).