r - 使用 geom_smooth 添加回归线以在 R 中使用离散 x 轴绘制

Question

我想将线性模型的回归线添加到 R 中的绘图。

我创建了以下示例数据集:

# Load libraries
library(tidyverse)
library(ggbeeswarm)

# Set seed
set.seed(123)

# Create dataset
ID <- sprintf("ID-%s",seq(1:30))
baseline <- rnorm(30, mean = 50, sd = 3)

df <- data.frame(ID, baseline) %>%
  mutate(`1` = baseline - rnorm(1, mean = 5, sd = 4), 
         `2` = `1` - rnorm(1, mean = 7, sd = 5), 
         `3` = `2` - rnorm(1, mean = 10, sd = 9)) %>% 
  pivot_longer(-ID) %>% 
  rename(time = name) %>% 
  mutate(time = as.factor(time))

创建以下图:

# Plot
ggplot(data = df, aes(x=time, y = value)) + 
  geom_quasirandom() +
  theme_classic() + 
  scale_x_discrete(limits = c("baseline", "1", "2", "3") ) +
  labs(x = "Time", y = "Value")

如果我将 geom_smooth(method = 'lm') 添加到绘图中，什么也不会发生，我认为这与 time 是一个因素有关.但是，添加 geom_smooth(method = 'lm', formula = y~as.numeric(x) 也不起作用。

如何在此图上绘制回归线？

EDIT1.0:我已经能够使用 geom_smooth 通过 geom_smooth(aes(x = as.numeric(time), y = value), method = "lm", formula = y~x) 绘制回归线，但遗憾的是，回归线不正确...

Answer 1

如何使用有序因子来启用 aes(as.numeric(time), value) 的叠加？

# Load libraries
library(tidyverse)
library(ggbeeswarm)

# Set seed
set.seed(123)

# Create dataset
ID <- sprintf("ID-%s",seq(1:30))
baseline <- rnorm(30, mean = 50, sd = 3)

df <- data.frame(ID, baseline) %>%
    mutate(`1` = baseline - rnorm(1, mean = 5, sd = 4), 
           `2` = `1` - rnorm(1, mean = 7, sd = 5), 
           `3` = `2` - rnorm(1, mean = 10, sd = 9)) %>% 
    pivot_longer(-ID) %>% 
    rename(time = name) %>% 
    # create ordered factor to allow synchronized order of x after as.numeric
    mutate(time = factor(time, ordered = T, c("baseline", "1", "2", "3")))  


## rendered results
ggplot(data = df, aes(x=time, y = value)) + 
    geom_quasirandom() +
    theme_classic() + 
    labs(x = "Time", y = "Value") +
    geom_smooth(aes(as.numeric(time), value), method = "lm")

## verify with this
ggplot(data = df, aes(x=time, y = value)) + 
    geom_point() +
    theme_classic() + 
    labs(x = "Time", y = "Value") +
    geom_smooth(aes(as.numeric(time), value), method = "lm")

^{由 reprex package 创建于 2020-04-15 (v0.3.0)}