Благодаря ответу Tjebo мне удалось создать функцию, которая отображает красивую цветную полосу, которая будет добавлена к графикам с помощью cowplot, patchwork или других подобных пакетов, как в его примере.
Вот оно: РЕДАКТИРОВАТЬ: вы также можете найти его на github
plot_discrete_cbar = function(
breaks, # Vector of breaks. If +-Inf are used, triangles will be added to the sides of the color bar
palette = "Greys", # RColorBrewer palette to use
colors = RColorBrewer::brewer.pal(length(breaks) - 1, palette), # Alternatively, manually set colors
direction = 1, # Flip colors? Can be 1 or -1
spacing = "natural", # Spacing between labels. Can be "natural" or "constant"
border_color = NA, # NA = no border color
legend_title = NULL,
legend_direction = "horizontal", # Can be "horizontal" or "vertical"
font_size = 5,
expand_size = 1, # Controls spacing around legend plot
spacing_scaling = 1, # Multiplicative factor for label and legend title spacing
width = 0.1, # Thickness of color bar
triangle_size = 0.1 # Relative width of +-Inf triangles
) {
require(ggplot2)
if (!(spacing %in% c("natural", "constant"))) stop("spacing must be either 'natural' or 'constant'")
if (!(direction %in% c(1, -1))) stop("direction must be either 1 or -1")
if (!(legend_direction %in% c("horizontal", "vertical"))) stop("legend_direction must be either 'horizontal' or 'vertical'")
breaks = as.numeric(breaks)
new_breaks = sort(unique(breaks))
if (any(new_breaks != breaks)) warning("Wrong order or duplicated breaks")
breaks = new_breaks
if (class(colors) == "function") colors = colors(length(breaks) - 1)
if (length(colors) != length(breaks) - 1) stop("Number of colors (", length(colors), ") must be equal to number of breaks (", length(breaks), ") minus 1")
if (!missing(colors)) warning("Ignoring RColorBrewer palette '", palette, "', since colors were passed manually")
if (direction == -1) colors = rev(colors)
inf_breaks = which(is.infinite(breaks))
if (length(inf_breaks) != 0) breaks = breaks[-inf_breaks]
plotcolors = colors
n_breaks = length(breaks)
labels = breaks
if (spacing == "constant") {
breaks = 1:n_breaks
}
r_breaks = range(breaks)
cbar_df = data.frame(stringsAsFactors = FALSE,
y = breaks,
yend = c(breaks[-1], NA),
color = as.character(1:n_breaks)
)[-n_breaks,]
xmin = 1 - width/2
xmax = 1 + width/2
cbar_plot = ggplot(cbar_df, aes(xmin=xmin, xmax = xmax, ymin = y, ymax = yend, fill = factor(color, levels = 1:length(colors)))) +
geom_rect(show.legend = FALSE,
color=border_color)
if (any(inf_breaks == 1)) { # Add < arrow for -Inf
firstv = breaks[1]
polystart = data.frame(
x = c(xmin, xmax, 1),
y = c(rep(firstv, 2), firstv - diff(r_breaks) * triangle_size)
)
plotcolors = plotcolors[-1]
cbar_plot = cbar_plot +
geom_polygon(data=polystart, aes(x=x, y=y),
show.legend = FALSE,
inherit.aes = FALSE,
fill = colors[1],
color=border_color)
}
if (any(inf_breaks > 1)) { # Add > arrow for +Inf
lastv = breaks[n_breaks]
polyend = data.frame(
x = c(xmin, xmax, 1),
y = c(rep(lastv, 2), lastv + diff(r_breaks) * triangle_size)
)
plotcolors = plotcolors[-length(plotcolors)]
cbar_plot = cbar_plot +
geom_polygon(data=polyend, aes(x=x, y=y),
show.legend = FALSE,
inherit.aes = FALSE,
fill = colors[length(colors)],
color=border_color)
}
if (legend_direction == "horizontal") { #horizontal legend
mul = 1
x = xmin
xend = xmax
cbar_plot = cbar_plot + coord_flip()
angle = 0
legend_position = xmax + 0.1 * spacing_scaling
} else { # vertical legend
mul = -1
x = xmax
xend = xmin
angle = -90
legend_position = xmax + 0.2 * spacing_scaling
}
cbar_plot = cbar_plot +
geom_segment(data=data.frame(y = breaks, yend = breaks),
aes(y=y, yend=yend),
x = x - 0.05 * mul * spacing_scaling, xend = xend,
inherit.aes = FALSE) +
annotate(geom = 'text', x = x - 0.1 * mul * spacing_scaling, y = breaks,
label = labels,
size = font_size) +
scale_x_continuous(expand = c(expand_size,expand_size)) +
scale_fill_manual(values=plotcolors) +
theme_void()
if (!is.null(legend_title)) { # Add legend title
cbar_plot = cbar_plot +
annotate(geom = 'text', x = legend_position, y = mean(r_breaks),
label = legend_title,
angle = angle,
size = font_size)
}
cbar_plot
}
Пример использования:
plot_discrete_cbar(c(1:10))
plot_discrete_cbar(c(0,2,5,10,20, Inf), palette="Reds")
plot_discrete_cbar(c(0,2,5,10,20, Inf), colors=rainbow, legend_direction="vertical", legend_title="A title! WOW!", border_color="red")
plot_discrete_cbar(c(-Inf, -8, -4, -2, -1, 1, 2, 4, 8, Inf), palette="BrBG", legend_title="Precipitation bias (mm/day)")
plot_discrete_cbar(c(-Inf, -8, -4, -2, -1, 1, 2, 4, 8, Inf), palette="BrBG", legend_title="Precipitation bias (mm/day)", spacing="constant")
