R-根据其他行和列中的值进行条件计算

Question

我的数据具有以下格式：-第一列：指示计算机是否正在运行-第二列：计算机运行的总时间

请参阅下面的数据集：

structure(c("", "running", "running", "running", "", "", "", 
"running", "running", "", "10", "15", "30", "2", "5", "17", "47", 
"12", "57", "87"), .Dim = c(10L, 2L), .Dimnames = list(NULL, 
    c("c", "v")))

我想添加第三列，以给出计算机已运行的总时间（通过添加自计算机开始运行以来的所有时间）。 请参阅以下所需的输出：

 [1,] ""        "10" "0"   
 [2,] "running" "15" "15"  
 [3,] "running" "30" "45"  
 [4,] "running" "2"  "47"  
 [5,] ""        "5"  "0"   
 [6,] ""        "17" "0"   
 [7,] ""        "47" "0"   
 [8,] "running" "12" "12"  
 [9,] "running" "57" "69"  
[10,] ""        "87" "0" 

我试图用R编写一些代码来以一种优雅的方式来获得它，但是目前我的编程技能太有限了。 有谁知道解决这个问题的方法吗？ 预先谢谢您！

Answer 1

首先，我们将您的数据转换为可以包含混合数据类型的更合适的数据结构：

m <- structure(c("", "running", "running", "running", "", "", "", 
                 "running", "running", "", "10", "15", "30", "2", "5", "17", "47", 
                 "12", "57", "87"), .Dim = c(10L, 2L), .Dimnames = list(NULL, 
                                                                        c("c", "v")))
DF <- as.data.frame(m, stringsAsFactors = FALSE)
DF[] <- lapply(DF, type.convert, as.is = TRUE)

然后，我们可以使用package data.table轻松地做到这一点：

library(data.table)
setDT(DF)
DF[, total := cumsum(v), by = rleid(c)]
DF[c == "", total := 0]
#          c  v total
# 1:         10     0
# 2: running 15    15
# 3: running 30    45
# 4: running  2    47
# 5:          5     0
# 6:         17     0
# 7:         47     0
# 8: running 12    12
# 9: running 57    69
#10:         87     0

Answer 2

这是使用基数R的简单解决方案：

DF$total <- ave(DF$v, DF$c, cumsum(DF$c == ""), FUN = cumsum)
DF$total[DF$c == ""] <- 0

> DF
         c  v total
1          10     0
2  running 15    15
3  running 30    45
4  running  2    47
5           5     0
6          17     0
7          47     0
8  running 12    12
9  running 57    69
10         87     0

Answer 3

我们可以使用dplyr

library(dplyr)
 DF %>% 
   group_by(cumsum(c==''),c) %>%
   mutate(total=replace(cumsum(v), c=='', 0) )