在 ggplot2 中叠加/叠加分组条形图

Question

我想制作一个条形图，其中包含两个时间点“之前”和“之后”的数据叠加。

在每个时间点，参与者都会被问到两个问题（“疼痛”和“恐惧”），他们会通过给出 1、2 或 3 的分数来回答。

我现有的代码很好地绘制了“之前”时间点的数据计数，但我似乎无法添加“之后”数据的计数。

这是我希望绘图在添加“之后”数据后的样子的草图，黑条代表“之后”数据：

我想在 ggplot2() 中绘制图，并且我尝试改编来自如何在 R 中叠加条形图的代码？ 但我无法让它用于分组数据。

非常感谢！

#DATA PREP
library(dplyr)
library(ggplot2)
library(tidyr)


df <- data.frame(before_fear=c(1,1,1,2,3),before_pain=c(2,2,1,3,1),after_fear=c(1,3,3,2,3),after_pain=c(1,1,2,3,1))


df <- df %>% gather("question", "answer_option") # Get the counts for each answer of each question 
df2 <- df  %>%
  group_by(question,answer_option) %>%
  summarise (n = n()) 
df2 <- as.data.frame(df2)


df3 <- df2 %>% mutate(time = factor(ifelse(grepl("before", question), "before", "after"),
                                        c("before", "after"))) # change classes and split data into two data frames
df3$n <- as.numeric(df3$n)
df3$answer_option <- as.factor(df3$answer_option)
df3after <- df3[ which(df3$time=='after'), ]
df3before <- df3[ which(df3$time=='before'), ]


# CODE FOR 'BEFORE' DATA ONLY PLOT - WORKS  
    ggplot(df3before, aes(fill=answer_option, y=n, x=question)) + geom_bar(position="dodge", stat="identity")



# CODE FOR 'BEFORE' AND 'AFTER' DATA PLOT - DOESN'T WORK
ggplot(mapping = aes(x, y,fill)) +
  geom_bar(data = data.frame(x = df3before$question, y = df3before$n, fill= df3before$index_value), width = 0.8, stat = 'identity') +
  geom_bar(data = data.frame(x = df3after$question, y = df3after$n, fill=df3after$index_value), width = 0.4, stat = 'identity', fill = 'black') +
  theme_classic() + scale_y_continuous(expand = c(0, 0))

Answer 1

我认为，线索是设置了width的酒吧“后”，但躲闪他们，就好像他们的宽度0.9（即相同的（默认）宽度“之前”吧）。另外，因为我们没有映射 fill“after”条，所以我们需要使用group审美来实现躲避。

我更喜欢只有一个数据集，并且在每次调用geom_col.

ggplot(mapping = aes(x = question, y = n, fill = factor(ans))) +
  geom_col(data = d[d$t == "before", ], position = "dodge") +
  geom_col(data = d[d$t == "after", ], aes(group = ans),
           fill = "black", width = 0.5, position = position_dodge(width = 0.9))

数据：

set.seed(2)
d <- data.frame(t = rep(c("before", "after"), each = 6),
                question = rep(c("pain", "fear"), each = 3),
                ans = 1:3, n = sample(12))

使用 的替代数据准备data.table，从您原来的“df”开始：

library(data.table)
d <- melt(setDT(df), measure.vars = names(df), value.name = "ans")
d[ , c("t", "question") := tstrsplit(variable, "_")]

要么预先计算计数并按上述方式继续 geom_col

# d2 <- d[ , .N, by = .(question, ans)]

或者让我们geom_bar计算：

ggplot(mapping = aes(x = question, fill = factor(ans))) +
  geom_bar(data = d[d$t == "before", ], position = "dodge") +
  geom_bar(data = d[d$t == "after", ], aes(group = ans),
           fill = "black", width = 0.5, position = position_dodge(width = 0.9))

数据：

df <- data.frame(before_fear = c(1,1,1,2,3), before_pain = c(2,2,1,3,1),
                     after_fear = c(1,3,3,2,3),after_pain = c(1,1,2,3,1))