在barplot ggplot中为每个组手动设置颜色

Question

我需要为条形图中的每个组手动设置颜色。我目前有填充=时间，这目前正在确定颜色。我们有5个品牌，每个品牌分别有2个月的价值。我需要按品牌分组，但是还需要一种显示哪个条形表示哪个月（时间）的方法，我目前可以执行此操作，但是我想为每个条形组上色。例如。brand1条=红色，brand2条=蓝色ect，同时仍有填充时间=时间

这是我的代码：

colors <- c("#98999B", "#F4C400", "#CB003D", "#6BABE5", "#E65400", "#542C82")

time <- c("February 2017","March 2017","February 2017","March 2017","February 2017","March 2017","February 2017","March 2017","February 2017","March 2017")
value <- as.numeric(c("3.08","3.64","1.61","1.81","-1.02","-1.09","-5.23","-5.08","-1.51","-1.43"))
brand <- c("brand1","brand1","brand2","brand2","brand3","brand3","brand4","brand4","brand5","brand5")

Monthly_BMS_df <- as.data.table(cbind(time,value,brand))

bar <- ggplot(Monthly_BMS_df, aes(brand, value, fill = time)) + 
  geom_bar(stat="identity", position = "dodge") +
 theme(legend.position='none') + scale_fill_manual(values=colors)

ggplotly(bar, width=1000,height=350)

Answer 1

一种选择是创建一个hcl调色板，每种调色板具有不同的色调，brand并且在不同品牌之间每个月的顺序亮度相同。例如：

library(ggplot2)
library(data.table)
library(plotly)

Monthly_BMS_df <- data.table(time, value, brand)

创建调色板：

nb = length(unique(Monthly_BMS_df$brand))
nm = length(unique(Monthly_BMS_df$time))

colors = apply(expand.grid(seq(70,40,length=nm), 100, seq(15,375,length=nb+1)[1:nb]), 1, 
               function(x) hcl(x[3],x[2],x[1]))

在下面的代码中，我们用来fill=interaction(time, brand)将不同的颜色映射到品牌和月份的每种组合。然后scale_fill_manual分配我们上面创建的调色板。每个月的亮度降低，因此三月比二月更暗。

bar <- ggplot(Monthly_BMS_df, aes(brand, value, fill=interaction(time, brand))) + 
  geom_hline(yintercept=0, colour="grey60") +
  geom_bar(stat="identity", position = "dodge", show.legend=FALSE) +
  scale_fill_manual(values=colors) +
  theme_classic()

ggplotly(bar, width=1000, height=350) 

作为上面图解的替代方法，折线图可以使比较每个品牌的趋势变得更加容易。

library(dplyr)

ggplot(Monthly_BMS_df, aes(time, value, group=brand, colour=brand)) + 
  geom_hline(yintercept=0, colour="grey60") +
  geom_text(data=Monthly_BMS_df %>% filter(time==min(time)),
            aes(label=brand), position=position_nudge(-0.25)) +
  geom_line(linetype="12", alpha=0.5, size=0.7) +
  geom_text(aes(label=value)) +
  guides(colour=FALSE) +
  theme_classic()