r - (日期)内的总和

Question

我正在尝试计算发生在同一日期的值的总和(在 XYZmin 中)。

我的数据看起来像这样，

bar <- structure(list(date = structure(c(15622, 15622, 15622, 15628, 
15632, 15635, 15639, 15639, 15639, 15639, 15639, 15642, 15646, 
15646, 15650, 15650, 15650, 15657, 15660, 15660, 15674, 15681, 
15691, 15695, 15709, 15716, 15723, 15730, 15737, 15737, 15737, 
15737, 15737, 15737, 15740, 15743, 15743, 15743, 15744, 15744, 
15744, 15744, 15746, 15751, 15755, 15758), class = "Date"), XYZmin = c(-20, 
-15, -10, -70, -60, -60, -95, -10, -10, -40, -25, -25, -20, -10, 
-3, -5, -25, -5, -70, -5, -30, -30, -25, 60, 60, 60, 60, 60, 
-10, -10, -30, -30, -10, -10, -10, -60, -30, -10, 75, -10, -10, 
-10, 60, 60, -15, 60)), .Names = c("date", "XYZmin"), class = "data.frame", row.names = c(NA, 
-46L))

head(bar)   
        date XYZmin
1 2012-10-09    -20
2 2012-10-09    -15
3 2012-10-09    -10
4 2012-10-15    -70
5 2012-10-19    -60
6 2012-10-22    -60

我正在努力完成的是创建一个新变量 XYZtot ，其中，在出现不止一次的数据中，对第二个数据的第一个和第二个值求和，并在第三个数据处对第一个、第二个和第三个值求和.这是我的目标的一个片段。

head(new_bar_with_XYZtot) 

        date XYZmin XYZtot
1 2012-10-09    -20    -20
2 2012-10-09    -15    -35
3 2012-10-09    -10    -40
4 2012-10-15    -70    -70
5 2012-10-19    -60    -60
6 2012-10-22    -60    -60

更新了大 microbenchmark 测试

alexwhan <- function(bar,date,XYZmin) ddply(bar, .(date), transform, XYZmin.sum = cumsum(XYZmin))

Arun <- function(bar,date,XYZmin) within(bar, {XYZtot <- ave( XYZmin, date, FUN=cumsum)})

agstudy <- function(bar,date,XYZmin) transform(bar, XYZtot = ave(XYZmin, date, FUN = cumsum))

# install.packages("data.table", dependencies = TRUE)
library(data.table)
mnel <- function(bar,date,XYZmin)  bar <- data.table(bar); bar[, XYZmin.sum := cumsum(XYZmin), by = date]

# install.packages("microbenchmark", dependencies = TRUE)
require(microbenchmark)

# run test
res <- microbenchmark(alexwhan(bar,date,XYZmin), Arun(bar,date,XYZmin), agstudy(bar,date,XYZmin), mnel(bar,date,XYZmin), times = 666)


## Print results:
print(res)

数字，

Unit: microseconds
                        expr       min        lq    median        uq       max neval
 alexwhan(bar, date, XYZmin) 14484.077 15056.613 15237.760 15945.482 72650.126   666
     Arun(bar, date, XYZmin)   963.632  1018.311  1070.759  1138.655  4988.226   666
  agstudy(bar, date, XYZmin)  1967.292  2021.115  2078.261  2158.689  9240.500   666
     mnel(bar, date, XYZmin)   251.312   270.295   282.821   325.040  6540.367   666


### Plot results:
boxplot(res)

Answer 1

也使用 ave 但使用 transform

transform(bar, XYZtot = ave(XYZmin, date, FUN = cumsum))

在 OP 评论后编辑

transform(bar, XYZtot = ave(XYZmin, date, FUN = 
                          function(x)
                            if(length(x) < 1) NA 
                            else c(cumsum(x[-length(x)]),NA)))