Hello everyone,

Can anyone show me how to replace the `color`

scale in `p1`

with the color bar `p2`

generated by `plot_discrete_cbar`

function?

Thanks for any suggestions!

```
library(ggplot2)
library(cowplot)
# discrete colorbar
plot_discrete_cbar = function (
# Vector of breaks. If +-Inf are used, triangles will be added to the sides of the color bar
breaks,
palette = "Greys", # RColorBrewer palette to use
# Alternatively, manually set colors
colors = RColorBrewer::brewer.pal(length(breaks) - 1, palette),
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 = color)) +
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)
}
return(cbar_plot)
}
# Cut data into bins
iris2 <- iris
values <- c(0, 1, 2, 5, 10)
iris2$cuts <- cut(iris2$Petal.Length, values)
p1 <- ggplot(iris2, aes(Sepal.Length, y = Sepal.Width,
size = Petal.Width,
color = cuts))+
geom_point() +
facet_grid(~ Species) +
scale_color_brewer("Petal.Length", palette = "RdYlBu") +
theme(legend.position = "bottom") +
guides(color = guide_legend(title.position = "top",
title.hjust = 0.5)) +
guides(size = guide_legend(label.position = "bottom",
title.position = "top",
title.hjust = 0.5,
override.aes = list(shape = c("circle open"),
color = c("grey50"))))
p1
```

```
p2 <- plot_discrete_cbar(c(-Inf, 0, 1, 2, 5, 10, Inf),
palette = "RdYlBu",
legend_title = "Petal.Length",
spacing = "natural")
p2
```

```
# Combine
plot_grid(p1,
p2,
nrow = 2,
rel_heights = c(1.5, 1.0))
```

Created on 2018-06-07 by the reprex package (v0.2.0).