R 绘图仪中的时间序列

所以，我有这些数据

test_data <- structure(list(
  time = c(29510, 29528.023023023, 29546.046046046, 
           29564.0690690691, 29582.0920920921, 29600.1151151151, 
           29618.1381381381, 29636.1611611612, 29654.1841841842, 
           29672.2072072072, 29690.2302302302, 29708.2532532533, 
           29726.2762762763, 29744.2992992993, 29762.3223223223, 
           29780.3453453453, 29798.3683683684, 29816.3913913914, 
           29834.4144144144, 29852.4374374374), 
  sum = c(0L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 2L, 5L, 7L, 9L, 9L, 15L, 
          17L, 18L, 18L, 18L, 18L, 21L)), 
  .Names = c("time", "sum"), 
  row.names = c(NA, 20L), 
  class = "data.frame")

但是当我尝试使用

plot\ly

时，时间作为数字而不是时间错误地显示出来。plotly中是否有类似于ggplot2的

scale\u x\u time

功能

plot_ly(test_data, x = ~time, y = ~sum, type = 'scatter', mode = 'lines')

---

那么，整合@Z.Lin的建议，消除一天中的必要性：

test_data$time <- as.POSIXct(test_data$time, origin = "1970-01-01")  # as date
test_data$time <- strftime(test_data$time,format="%H:%M:%S")         # remove the day
plot_ly(test_data, x = ~time, y = ~sum, type = 'scatter', mode = 'lines')

---

test_data$time这几乎可以工作，尽管我不喜欢使用ggplot设置。但是重叠行时出现的文本仍然显示数字而不是时间如果将
time
变量转换为date-time类，则
plot\ly
代码将正常工作。例如：
测试数据$time
test_data$time <- as.POSIXct(test_data$time, origin = "1970-01-01")  # as date
test_data$time <- strftime(test_data$time,format="%H:%M:%S")         # remove the day
plot_ly(test_data, x = ~time, y = ~sum, type = 'scatter', mode = 'lines')