处理图像重叠

ggplot中，geom_jitter()和position_jitter()都是处理点的处理图像重叠的问题。

如图，

library(tidyverse)
library(lubridate)
data1 <- tibble::tribble(
   ~logtype,            ~inserttime,
   "APP主登录",  "2017-07-29 13:10:31",
     "延伸登录",  "2017-08-29 19:03:12",
     "延伸登录",  "2017-08-29 19:07:17",
     "独立登录",  "2017-08-31 17:28:07",
     "独立登录",  "2017-08-31 17:28:07",
     "独立登录",  "2017-08-31 17:45:24",
     "独立登录",  "2017-09-05 02:31:37",
     "独立登录",  "2017-09-05 02:32:15",
     "独立登录",  "2017-09-05 02:34:50",
    "M站主登录",  "2017-09-05 02:52:02"
  ) %>% 
  rename(item=logtype, start = inserttime) %>%
  mutate(start = ymd_hms(start))
data1 %>% 
  # mutate(start = as.Date(start)) %>% 
  ggplot(aes(x = start, y = fct_reorder(item, start, .desc = TRUE))
         ) + 
    geom_point(
                # position=position_jitter(width=0.5,height=0),
                size = 6, 
                alpha = 0.5,
                col = 'gold'
              ) +
    xlab(NULL) + 
    ylab(NULL) +
    theme_light() +
    theme(
      legend.position = "none",
      panel.border = element_blank(),
    ) +
    theme(text = element_text(family = 'STKaiti', size=10)) 

发现图中有图重合现象，这是因为独立登录发生时间太过于相近。

处理的方法是将比较相近的相同登录，转为同一时间，函数为 mutate(start = as.Date(start))

然后加入jitter函数， position=position_jitter(width=0.5,height=0)。 其中，height=0表示控制点不纵向扰动。

data1 %>% 
  mutate(start = as.Date(start)) %>%
  ggplot(aes(x = start, y = fct_reorder(item, start, .desc = TRUE))
         ) + 
    geom_point(
                position=position_jitter(width=0.5,height=0),
                size = 6, 
                alpha = 0.5,
                col = 'gold'
              ) +
    xlab(NULL) + 
    ylab(NULL) +
    theme_light() +
    theme(
      legend.position = "none",
      panel.border = element_blank(),
    ) +
    theme(text = element_text(family = 'STKaiti', size=10))