ggplot - multiple different geom_vlines with differing lengths

Question

I am trying to emulate the image shown where the vertical lines stop at the data points. Is there a way to give geom_vlines a specific length? I have included example code below to show what I have right now. I want each vline to stop when it intercepts a point.

library(tidyverse)
library(lubridate)
library(scales)

dates <- c("2021-01-01", "2021-02-01", "2021-03-01")
values <- c(1,2,3)
df <- data.frame(dates, values)
df <- df %>% 
  mutate(dates = date(dates))

df %>% 
  ggplot(aes(dates, values)) +
    geom_point() +
    theme_minimal() +
    scale_y_continuous(limits = c(0,3)) +
    theme(
      panel.grid.minor.y = element_blank(),
      panel.grid.major.x = element_blank(),
      panel.grid.minor.x = element_blank(),
      axis.title.x = element_blank(),
      axis.title.y = element_blank()
    ) +
    geom_vline(xintercept = as.numeric(as.Date("2021-01-01"))) +
    geom_vline(xintercept = as.numeric(as.Date("2021-02-01"))) +
    geom_vline(xintercept = as.numeric(as.Date("2021-03-01")))

Answer 1

You can do this using geom_segment instead of geom_vline.

df %>% 
  ggplot(aes(dates, values)) +
  geom_point() +
  geom_segment(aes(x = dates, xend = dates, y = 0, yend = values), color = "red") + 
  theme_minimal() +
  scale_y_continuous(limits = c(0,3)) +
  theme(
    panel.grid.minor.y = element_blank(),
    panel.grid.major.x = element_blank(),
    panel.grid.minor.x = element_blank(),
    axis.title.x = element_blank(),
    axis.title.y = element_blank()
  )

Result: