问题描述
在使用函数 c("red","blue","grey50","black") 和 ggplot 代码时，我想使用我自己的填充颜色（例如：scale_fill_binned()）。我该怎么做？
这是一个最小的可重现示例：
library(tidyverse)
dat <- mtcars %>%
group_by(cyl) %>%
summarise(n = n(),mean_hp = mean(hp)) %>%
ungroup
ggplot(data = dat,aes(x = cyl,y = mean_hp,size = n,fill = n)) +
geom_point(shape = 21) +
scale_size_binned(breaks = c(8,10,12),guide = guide_bins(show.limits = T)) +
scale_fill_binned(breaks = c(8,guide = guide_bins(show.limits = T),type = "viridis") +
labs(x = "Cylinder",y = "Mean hp",fill = "Nb of cars",size = "Nb of cars") +
theme_minimal()
输出如下：
解决方法
要使用这一系列函数，您需要提供一个函数，该函数返回一个类为 def characters(a=""):
character_keys = list(Characters.keys())
if a:
return character_keys
else:
print(character_keys)
的对象（即等效于 "ScaleContinuous" "Scale" "ggproto" "gg" 的输出）！
scale_fill_viridis_c
请注意，您使用颜色作为尺度，通过眼睛将其转换为具有数字意义的差异。颜色是在手动应用的点之间插入的，因此实际上不会是您的确切颜色。如果您希望按颜色划分平均值，最好先创建一个因子，然后手动应用您的主题。
scale_fill_custom <- function (...,alpha = 1,begin = 0,end = 1,direction = 1,option = "D",values = NULL,space = "Lab",na.value = "grey50",guide = "colourbar",aesthetics = "fill") {
continuous_scale(aesthetics,scale_name = "custom",palette = scales:::gradient_n_pal(c("red","blue","grey50","black"),values,space),na.value = na.value,guide = guide,...)
}
ggplot(data = dat,aes(x = cyl,y = mean_hp,size = n,fill = n)) +
geom_point(shape = 21) +
scale_size_binned(breaks = c(8,10,12),guide = guide_bins(show.limits = T)) +
scale_fill_binned(breaks = c(8,guide = guide_bins(show.limits = T),type = scale_fill_custom) +
labs(x = "Cylinder",y = "Mean hp",fill = "Nb of cars",size = "Nb of cars") +
theme_minimal()
通过@teunbrand 的评论，我能够想出一些东西。
cols <- c("red","black")
ggplot(data = dat,guide = guide_bins(show.limits = T)) +
labs(x = "Cylinder",size = "Nb of cars") +
theme_minimal() +
binned_scale(aesthetics = "fill",palette = ggplot2:::binned_pal(scales::manual_pal(values = cols)),guide = "bins",breaks = c(8,limits = c(min(dat$n),max(dat$n)),show.limits = T)
输出如下：
