如何为plyr创建函数

I have a series of soccer results and wish to find out how many points a team has scored in a particular number of games

我有一系列的足球成绩，并希望了解一支球队在特定数量的比赛中得分的数量

Here is the head of a subset with the cumulative points scored during a season since the latest result

这是自最新结果以来在一个赛季中得分累积分数的子集的头部

I have been wrist=-slapped a couple of times for not using dput so bear with length

因为没有使用dput所以我已经做了几次手腕因为长度不合适

allData <- structure(list(team = c("Arsenal", "Tottenham H", "Tottenham H", 
"Arsenal", "Arsenal", "Tottenham H"), venue = c("H", "A", "H", 
"A", "H", "A"), result = c("W", "D", "W", "L", "W", "D"), GF = c(1L, 
0L, 3L, 1L, 3L, 0L), GA = c(0L, 0L, 1L, 2L, 0L, 0L), gameDate = structure(c(1333868400, 
1333782000, 1333263600, 1333177200, 1332572400, 1332572400), class = c("POSIXct", 
"POSIXt"), tzone = ""), season = structure(c(2L, 2L, 2L, 2L, 
2L, 2L), .Label = c("2010/2011", "2011/2012"), class = "factor"), 
 points = c(3, 1, 3, 0, 3, 1), GD = c(1L, 0L, 2L, -1L, 3L, 
0L), cumpts = c(3, 1, 4, 3, 6, 5)), .Names = c("team", "venue", 
"result", "GF", "GA", "gameDate", "season", "points", "GD", "cumpts"
), row.names = c(NA, 6L), class = "data.frame")

and here is the data for one team during one season

这是一个赛季中一支球队的数据

spurs <- structure(list(team = c("Tottenham H", "Tottenham H", "Tottenham H", 
"Tottenham H", "Tottenham H", "Tottenham H", "Tottenham H", "Tottenham H", 
"Tottenham H", "Tottenham H", "Tottenham H", "Tottenham H", "Tottenham H", 
"Tottenham H", "Tottenham H", "Tottenham H", "Tottenham H", "Tottenham H", 
"Tottenham H", "Tottenham H", "Tottenham H", "Tottenham H", "Tottenham H", 
"Tottenham H", "Tottenham H", "Tottenham H", "Tottenham H", "Tottenham H", 
"Tottenham H", "Tottenham H", "Tottenham H", "Tottenham H"), 
    venue = c("A", "H", "A", "H", "A", "H", "A", "H", "A", "H", 
    "A", "H", "H", "H", "A", "A", "H", "H", "A", "H", "A", "H", 
    "A", "H", "A", "A", "H", "A", "H", "A", "H", "A"), result = c("D", 
    "W", "D", "D", "L", "L", "L", "W", "D", "W", "L", "D", "W", 
    "W", "D", "W", "D", "W", "L", "W", "W", "W", "W", "W", "W", 
    "D", "W", "W", "W", "W", "L", "L"), GF = c(0L, 3L, 0L, 1L, 
    0L, 1L, 2L, 5L, 0L, 3L, 2L, 1L, 2L, 1L, 1L, 2L, 1L, 1L, 1L, 
    3L, 3L, 2L, 3L, 3L, 2L, 2L, 2L, 2L, 4L, 2L, 1L, 0L), GA = c(0L, 
    1L, 0L, 1L, 1L, 3L, 5L, 0L, 0L, 1L, 3L, 1L, 0L, 0L, 1L, 0L, 
    1L, 0L, 2L, 0L, 1L, 0L, 1L, 1L, 1L, 2L, 1L, 1L, 0L, 0L, 5L, 
    3L), gameDate = structure(c(1333782000, 1333263600, 1332572400, 
    1332313200, 1331366400, 1330848000, 1330243200, 1328947200, 
    1328515200, 1327996800, 1327219200, 1326528000, 1326268800, 
    1325577600, 1325318400, 1324972800, 1324540800, 1324281600, 
    1323590400, 1322899200, 1322294400, 1321862400, 1320562800, 
    1319958000, 1319353200, 1318748400, 1317538800, 1316847600, 
    1316329200, 1315638000, 1314514800, 1313996400), class = c("POSIXct", 
    "POSIXt"), tzone = ""), season = structure(c(2L, 2L, 2L, 
    2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 
    2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L), .Label = c("2010/2011", 
    "2011/2012"), class = "factor"), points = c(1, 3, 1, 1, 0, 
    0, 0, 3, 1, 3, 0, 1, 3, 3, 1, 3, 1, 3, 0, 3, 3, 3, 3, 3, 
    3, 1, 3, 3, 3, 3, 0, 0), GD = c(0L, 2L, 0L, 0L, -1L, -2L, 
    -3L, 5L, 0L, 2L, -1L, 0L, 2L, 1L, 0L, 2L, 0L, 1L, -1L, 3L, 
    2L, 2L, 2L, 2L, 1L, 0L, 1L, 1L, 4L, 2L, -4L, -3L), cumpts = c(1, 
    4, 5, 6, 6, 6, 6, 9, 10, 13, 13, 14, 17, 20, 21, 24, 25, 
    28, 28, 31, 34, 37, 40, 43, 46, 47, 50, 53, 56, 59, 59, 59
    )), .Names = c("team", "venue", "result", "GF", "GA", "gameDate", 
"season", "points", "GD", "cumpts"), row.names = c(NA, -32L), class = "data.frame")

I then have this code on the spurs dataframe to calculate points scored in specific game lengths(here 5)

然后我在马刺数据帧上有这个代码来计算特定游戏长度得分（这里是5）

gameLength <- 5
seasonLength <- nrow(spurs)
cumPoints <- c()
cumPoints[1] <- spurs[gameLength,]$cumpts
for (i in gameLength+1:seasonLength) {
cumPoints[i-(gameLength-1)] <- ((spurs[i,]$cumpts)- 
 (spurs[i-gameLength,]$cumpts))
}
cumPoints <- cumPoints[!is.na(cumPoints)] # not sure why throws up NAs

This produces the correct output

这会产生正确的输出

 [1]  6  5  2  4  4  7  7  8  8 10  8 11 11 11  8 10 10 12 12 15 15
[22] 13 13 13 13 13 12  9

but I need to be able to transform the allData with a column containing this data for every season and team in the dataframe.

但我需要能够在数据框中为每个季节和团队使用包含此数据的列转换allData。

I am assuming I should use ddply somehow, unless there is a better alternative

我假设我应该以某种方式使用ddply，除非有更好的选择

1 个解决方案

#1

To replicate your output:

要复制输出：

library(zoo)
rollapply(spurs$GD, gamelength, sum)

And if you have allData that looks like the spurs data.frame...

如果你有allData看起来像马刺data.frame ...

rollsum <- function(df, gamelen=gamelength) {
  require(zoo)
  out <- rollapply(df$points, gamelen, sum)

  return(out)
}

ddply(allData, .(team), rollsum)

#1