在ggplot中向条形图添加颜色时如何保持事件的顺序答案

【问题标题】：How to keep sequential order of events when adding color to barplot in ggplot在ggplot中向条形图添加颜色时如何保持事件的顺序
【发布时间】：2017-08-08 21:13:47
【问题描述】：

我正在尝试创建一个情节来描述我的学生随着时间的推移的行为。添加颜色时，我无法获得正确的事件顺序。例如，当我使用以下代码时，我得到了正确的事件顺序，但没有得到颜色：

ggplot(data=activity_timeline, aes(x=" ", y = Total.Time))+
  geom_bar(stat="identity", color="black")+
  facet_grid(facets=Name~.)+
  scale_fill_manual(values = c("red", "blue", "gray", "yellow", "purple", "orange", "green"),
                    name= "The student was doing:",
                    labels = c("Analysis", "Implementation", "None", "Organizing", "Planning", "Research", "Verification"))+
  ggtitle("                                           Time Spent on Problem Solving Activities")+
  labs(y = "Time in seconds", x = " ")+
  coord_flip()+
  theme(legend.position = "bottom", plot.title = element_text(size = 12),
        strip.text.y = element_text(size=12),
        strip.text.x = element_text(size=12),
        axis.title.x=element_text(size=12),
        legend.text=element_text(size=12),
        legend.title=element_text(size=12))

正确的顺序，没有颜色

当我添加颜色选项（第 2 行）时，图表会将具有相同操作的所有项目组合在一起。我使用的代码是：

ggplot(data=activity_timeline, aes(x=" ", y = Total.Time))+
  geom_bar(stat="identity", color="black", aes(fill=Action))+
  facet_grid(facets=Name~.)+
  scale_fill_manual(values = c("red", "blue", "gray", "yellow", "purple", "orange", "green"),
                    name= "The student was doing:",
                    labels = c("Analysis", "Implementation", "None", "Organizing", "Planning", "Research", "Verification"))+
  ggtitle("                                           Time Spent on Problem Solving Activities")+
  labs(y = "Time in seconds", x = " ")+
  coord_flip()+
  theme(legend.position = "bottom", plot.title = element_text(size = 12),
        strip.text.y = element_text(size=12),
        strip.text.x = element_text(size=12),
        axis.title.x=element_text(size=12),
        legend.text=element_text(size=12),
        legend.title=element_text(size=12))

错误的顺序，有颜色

我对 ggplot 完全陌生，并且使用我在网上找到的代码来执行此操作。我试图使用“时间线”功能，但我不知道如何让它与我的数据一起使用。如果有人对如何修复此代码有任何建议，我将不胜感激。

【问题讨论】：

标签： r ggplot2 colors geom-bar

【解决方案1】：

如果您希望按特定顺序排列堆叠条形，您可以在数据集中创建一个额外的列来指示该顺序。否则，我相信 geom_bar 默认按填充颜色对条形图进行排序。

这是一个示例数据集用于说明：

set.seed(1)
df <- data.frame(t = rexp(100, rate = 0.1),
                 student = c(rep("s1", 50), rep("s2", 50)),
                 activity = sample(c("a", "b", "c"), 100, replace = T),
                 seq = c(seq(1, 50, 1), seq(1, 50, 1)))

# without group parameter
ggplot(df, aes(x = "", y = t, fill = activity)) +
  geom_bar(stat = "identity", colour = "black") +
  facet_grid(student~.) +
  labs(y="time", x = "") +
  coord_flip()

# with group parameter
ggplot(df, aes(x = "", y = t, fill = activity, group = seq)) +
  geom_bar(stat = "identity", colour = "black") +
  facet_grid(student~.) +
  labs(y="time", x = "") +
  coord_flip()

【讨论】：