R在4天内计算总计数

在数据框

dataAlog

中，使用变量

'CashInd'

，

'ACCOUNT'

，

'DateTime'

和

'Cnt'

（所有观察值均为1）。每个

账户和
现金ind
在4天内的合计计数。我尝试使用for循环来处理速度较慢的问题。我想改用
apply
函数

for (i in 1:dim(dataAlog)[1]) {
  data <- subset(dataAlog, (dataAlog$CashInd==dataAlog$CashInd[i] & dataAlog$ACCOUNT==dataAlog$ACCOUNT[i]) & (dataAlog$DateTime<=dataAlog$DateTime[i]) & (dataAlog$DateTime >= as.POSIXct(as.Date(dataAlog$DateTime[i])-4)) )
  if (dim(data)[1]==0) {
    dataAlog$day4Count[i] <- 1
  }
  else{
    agg <- aggregate(cnt ~ ACCOUNT, data = data, FUN=sum)
    dataAlog$day4Count[i] <- agg$cnt
  }
}

for（i in 1:dim（dataAlog）[1]）{
数据这里是一个使用
data.table
的建议解决方案。您可以使用4个滚动窗口，从窗口中的最新日期开始计算4天前之后的日期数

数据：

另请参见
中的解决方案2。是否有您使用的示例
dataAlog
dataframe，以及您期望的输出？这将有助于测试for循环。感谢您的帮助！它可以工作。如果我有一个字段，如Amt，如何计算累计金额？很抱歉，我是data.table的新手。谢谢again@useR，我更新了您的累计金额。您能检查一下这是否是您想要的吗？您好@Chinsoon谢谢您的及时回复。我想在CashInd、ACCOUNT和4天窗口内计算累计金额。谢谢again@userR，更新为更可读的格式，并添加参考链接Thank@chinsoon！
library(zoo)
library(data.table)

#generate sample data
set.seed(0L)
N <- 20
dat <- data.table(CashInd=rep(1:2, N),
    ACCOUNT=rep(LETTERS[1:2], each=N),
    DateTime=sample(seq(Sys.Date()-2*N, Sys.Date(), "1 day"), N),
    Amt=rnorm(2*N))
#it is impt that the data is sorted
setorder(dat, CashInd, ACCOUNT, DateTime)

#roll with window of 4 and calculate the number of dates after the date 4 days ago of latest date
nDaysAgo <- 4
dat[, c("COUNT", "CumuAmt") := {
        list(sapply(DateTime, function(day) sum(between(DateTime, day-nDaysAgo, day))),
            sapply(DateTime, function(day) sum(Amt[between(DateTime, day-nDaysAgo, day)])))
    },
    by = c("CashInd", "ACCOUNT")]

#     CashInd ACCOUNT   DateTime         Amt COUNT     CumuAmt
#  1:       1       A 2018-02-24 -0.22426789     1 -0.22426789
#  2:       1       A 2018-02-28  0.13333636     2 -0.09093152
#  3:       1       A 2018-03-07  1.08576936     1  1.08576936
#  4:       1       A 2018-03-09 -1.14765701     2 -0.06188765
#  5:       1       A 2018-03-17 -1.28459935     1 -1.28459935
#  6:       1       A 2018-03-26  0.25222345     1  0.25222345
#  7:       1       A 2018-03-28 -0.29921512     2 -0.04699167
#  8:       1       A 2018-03-31  0.76359346     2  0.46437834
#  9:       1       A 2018-04-01  0.43568330     3  0.90006164
# 10:       1       A 2018-04-03 -0.05710677     3  1.14216999
# 11:       1       B 2018-02-24  1.75790309     1  1.75790309
# 12:       1       B 2018-02-28 -0.45278397     2  1.30511912
# 13:       1       B 2018-03-07 -1.56378205     1 -1.56378205
# 14:       1       B 2018-03-09 -0.43331032     2 -1.99709237
# 15:       1       B 2018-03-17  0.83204713     1  0.83204713
# 16:       1       B 2018-03-26  0.99216037     1  0.99216037
# 17:       1       B 2018-03-28  0.72675075     2  1.71891111
# 18:       1       B 2018-03-31 -0.23570656     2  0.49104419
# 19:       1       B 2018-04-01  1.23830410     3  1.72934829
# 20:       1       B 2018-04-03 -1.16657055     3 -0.16397300
# 21:       2       A 2018-03-01  0.37739565     1  0.37739565
# 22:       2       A 2018-03-02 -0.41151083     2 -0.03411519
# 23:       2       A 2018-03-03  0.04672617     3  0.01261099
# 24:       2       A 2018-03-05 -0.79900925     4 -0.78639826
# 25:       2       A 2018-03-12 -0.69095384     1 -0.69095384
# 26:       2       A 2018-03-14  0.80418951     2  0.11323567
# 27:       2       A 2018-03-15 -1.23753842     3 -1.12430275
# 28:       2       A 2018-03-16 -0.28946157     4 -1.41376433
# 29:       2       A 2018-03-27 -0.89192113     1 -0.89192113
# 30:       2       A 2018-03-29  0.50360797     2 -0.38831316
# 31:       2       B 2018-03-01  0.56074609     1  0.56074609
# 32:       2       B 2018-03-02  1.15191175     2  1.71265784
# 33:       2       B 2018-03-03 -0.22732869     3  1.48532915
# 34:       2       B 2018-03-05 -0.54288826     4  0.94244090
# 35:       2       B 2018-03-12  1.15653700     1  1.15653700
# 36:       2       B 2018-03-14 -0.83204330     2  0.32449370
# 37:       2       B 2018-03-15 -0.27934628     3  0.04514742
# 38:       2       B 2018-03-16 -0.64947165     4 -0.60432423
# 39:       2       B 2018-03-27 -0.42951311     1 -0.42951311
# 40:       2       B 2018-03-29 -1.06559058     2 -1.49510369
#     CashInd ACCOUNT   DateTime         Amt COUNT     CumuAmt