R ：通过 cut + ggplot 迅速画出 按时段 week / month 统计图

见：Plot Weekly or Monthly Totals in R

切 week / month :

log$Month <- as.Date(cut(log$Date,  breaks = "month"))

log$Week <- as.Date(cut(log$Date,  breaks = "week",  start.on.monday = FALSE))

统计并画图：

ggplot(data = log,

  aes(Month, Quantity)) +

  stat_summary(fun.y = sum, # adds up all observations for the month

    geom = "bar") + # or "line"

  scale_x_date(

    labels = date_format("%Y-%m"),

    breaks = "1 month") # custom x-axis labels


用ggplot2画折线图、面积图、直方图等等，笔记：chart_example