R中产品的订单日期之间的平均差异

Question

我有这种格式的数据集

Order_Name  Frequency  Order_Dt
A                2       2016-01-20
A                2       2016-05-01
B                1       2016-02-12
C                3       2016-03-04
C                3       2016-07-01
C                3       2016-08-09

我需要找到已经放置超过1次的那些订单的日期之间的平均差异，即频率＆gt; 1.

Answer 1

require(dplyr) 
# loading the data
df0 <- read.table(text = 
'Order_Name  Frequency  Order_Dt
A                2       2016-01-20
A                2       2016-05-01
B                1       2016-02-12
C                3       2016-03-04
C                3       2016-07-01
C                3       2016-08-09',
stringsAsFactors = F,
header = T)

# putting the date in the right format
df0$Order_Dt <- as.Date(df0$Order_Dt)

# obtaining the averages
df0 %>% filter(Frequency > 1) %>%    
  arrange(., Order_Name, Order_Dt) %>%
  mutate(diff_date = Order_Dt - lag(Order_Dt)) %>%
  group_by(Order_Name) %>%
  summarise(avg_days = mean(diff_date, na.rm = T))

# A tibble: 2 × 2
  Order_Name       avg_days
       <chr>         <time>
1          A 102.00000 days
2          C  33.33333 days