在不使用 dcast 的情况下重塑 R 中的数据（reshape2）答案

【问题标题】：Reshaping data in R without using dcast (reshape2)在不使用 dcast 的情况下重塑 R 中的数据（reshape2）
【发布时间】：2013-08-15 16:47:05
【问题描述】：

我的 dcast Rcode 不再运行。我有这里讨论的问题：segfault in R using reshape2 package and dcast

该错误尚未修复，因此我正在寻找其他方法来实现我的 dcast 输出。任何建议将不胜感激！

低于我的数据集的一个非常小的 dput。基本上，每个调查 ID（“EID”）每个物种都有一个条目。我想为每个调查 ID（“EID”）获取一个条目，其中我的所有物种作为列及其相关值（“值”），即宽格式。

> dput(sample)
structure(list(EID = c("L00155/69/2000-09-06", "Q99107/178/1999-08-23", 
"G02192/1/2002-07-08", "G97158/1/1997-10-26", "Q06091/2/2006-07-04", 
"L00004/171/2000-03-01", "G11094/15/2011-09-05", "Q04127/16/2004-07-28", 
"Q02122/230/2002-10-29", "G08002/6/2008-02-03", "Q99006/143/1999-02-17", 
"Q08053/3/2008-06-12", "Q99128/22/1999-08-19", "L00177/83/2000-12-18", 
"Q05122/11/2005-08-30", "Q04156/44/2004-10-29", "L01097/69/2001-06-26", 
"G08004/169/2008-05-14", "Q03041/26/2003-06-14", "G98115/60/1998-09-11", 
"G00002/20/2000-01-17", "G00002/20/2000-01-17", "G00054/1/2000-05-31", 
"G00054/1/2000-05-31"), tspp.name = structure(c(13L, 13L, 13L, 
13L, 16L, 13L, 13L, 4L, 13L, 13L, 13L, 13L, 13L, 11L, 4L, 13L, 
13L, 13L, 13L, 20L, 13L, 13L, 24L, 24L), .Label = c("American plaice", 
"American sand lance", "Arctic cod", "Atlantic cod", "Atlantic halibut", 
"Atlantic herring", "Bigeye tuna", "Black dogfish", "Bluefin tuna", 
"Capelin", "Greenland halibut", "Lookdown", "Northern shrimp", 
"Ocean quahog", "Porbeagle", "Redfishes", "Slenteye headlightfish", 
"Smooth flounder", "Spiny dogfish", "Striped pink shrimp", "Summer flounder", 
"White hake", "Winter flounder", "Witch flounder", "Yellowtail flounder"
), class = "factor"), elasmo.name = structure(c(26L, 30L, 30L, 
30L, 30L, 25L, 21L, 30L, 30L, 30L, 30L, 21L, 30L, 5L, 30L, 30L, 
30L, 21L, 30L, 30L, 14L, 21L, 24L, 21L), .Label = c("Arctic skate", 
"Atlantic sharpnose shark", "Barndoor skate", "Basking shark", 
"Black dogfish", "Blue shark", "Deepsea cat shark", "Greenland shark", 
"Jensen's skate", "Little skate", "Manta", "Ocean quahog", "Oceanic whitetip shark", 
"Porbeagle", "Portuguese shark", "Rough sagre", "Roughtail stingray", 
"Round skate", "Sharks", "Shortfin mako", "Skates", "Smooth skate", 
"Soft skate", "Spiny dogfish", "Spinytail skate", "Thorny skate", 
"White shark", "White skate", "Winter skate", "NA"), class = "factor"), 
    elasmo.discard = c(1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 0, 
    25, 0, 0, 0, 1, 0, 0, 1, 1, 15, 25)), .Names = c("EID", "tspp.name", 
"elasmo.name", "elasmo.discard"), class = "data.frame", row.names = c("18496", 
"488791", "87549", "236671", "139268", "15606", "11132", "115531", 
"93441", "159675", "403751", "42587", "485941", "19285", "130395", 
"119974", "73826", "7953", "99124", "351461", "71", "72", "184", 
"185"))

最后，我希望得到这个：

library(plyr)
test<-dcast(sample, ...~elasmo.name,value.var ="elasmo.discard",fun.aggregate=sum)
test

请注意，“dcast”代码在这里有效，但是当我在包含 145349 行的整个数据集上运行它时，我确实遇到了致命错误。

非常感谢！！

【问题讨论】：

这真的不是问这个问题的正确方法。根据定义，段错误是错误，应发送给维护者。在这种情况下，这可能会达到这个目的，因为作者是一名普通的 SO 读者，但总的来说不像电子邮件那样礼貌（或高效）。
好的。谢谢@DWin，我希望有人可以为我提供有关如何在不使用 dcast 的情况下重塑我的数据框的建议。
没有例子就很难提供帮助。
@djhurio，我添加了一个可重现的示例。

标签： r data-structures crash reshape2

【解决方案1】：

这将是之前的 Hadley 方法；先聚合得到总和，然后再整形。

foo <- aggregate(d[,4,drop=FALSE], by=d[,1:3], sum)
reshape(foo, v.names="elasmo.discard", idvar=c("EID", "tspp.name"), 
             timevar="elasmo.name", direction="wide")

如果第一部分速度较慢，“by”部分中的列可能会有所减少；看起来tspp.name 是由EID 定义的，如果是这样，请不要对其进行聚合，而是在事后添加它。

如果第二部分很慢，不妨试试这里的其中一种方法： https://stackoverflow.com/a/9617424/210673.

为了在加快速度方面获得更好的帮助，请提供一个可以测试代码的适当示例（可能使用示例或代表）。求解速度通常取决于每个变量有多少独特组合。

【讨论】：

谢谢@Aaron，我正在尝试在我的数据集上使用它，但遇到了一些麻烦...... drop=F 是什么意思？
这只是将其保留为单列数据框而不是简单的向量；原因是为了保留列名。
谢谢！它有效......但是，它需要安静一些时间！有什么方法可以让我更快地做到这一点？

【解决方案2】：

我无法重现该错误。请参阅随附的代码。我已将sample 的行号增加到196608。

可能sample$elasmo.name 中的类别数量起作用。

library(reshape2)

sample <- structure(list(EID = c("L00155/69/2000-09-06", "Q99107/178/1999-08-23", 
  "G02192/1/2002-07-08", "G97158/1/1997-10-26", "Q06091/2/2006-07-04", 
  "L00004/171/2000-03-01", "G11094/15/2011-09-05", "Q04127/16/2004-07-28", 
  "Q02122/230/2002-10-29", "G08002/6/2008-02-03", "Q99006/143/1999-02-17", 
  "Q08053/3/2008-06-12", "Q99128/22/1999-08-19", "L00177/83/2000-12-18", 
  "Q05122/11/2005-08-30", "Q04156/44/2004-10-29", "L01097/69/2001-06-26", 
  "G08004/169/2008-05-14", "Q03041/26/2003-06-14", "G98115/60/1998-09-11", 
  "G00002/20/2000-01-17", "G00002/20/2000-01-17", "G00054/1/2000-05-31", 
  "G00054/1/2000-05-31"), tspp.name = structure(c(13L, 13L, 13L, 
  13L, 16L, 13L, 13L, 4L, 13L, 13L, 13L, 13L, 13L, 11L, 4L, 13L, 
  13L, 13L, 13L, 20L, 13L, 13L, 24L, 24L), .Label = c("American plaice", 
  "American sand lance", "Arctic cod", "Atlantic cod", "Atlantic halibut", 
  "Atlantic herring", "Bigeye tuna", "Black dogfish", "Bluefin tuna", 
  "Capelin", "Greenland halibut", "Lookdown", "Northern shrimp", 
  "Ocean quahog", "Porbeagle", "Redfishes", "Slenteye headlightfish", 
  "Smooth flounder", "Spiny dogfish", "Striped pink shrimp", "Summer flounder", 
  "White hake", "Winter flounder", "Witch flounder", "Yellowtail flounder"
  ), class = "factor"), elasmo.name = structure(c(26L, 30L, 30L, 
  30L, 30L, 25L, 21L, 30L, 30L, 30L, 30L, 21L, 30L, 5L, 30L, 30L, 
  30L, 21L, 30L, 30L, 14L, 21L, 24L, 21L), .Label = c("Arctic skate", 
  "Atlantic sharpnose shark", "Barndoor skate", "Basking shark", 
  "Black dogfish", "Blue shark", "Deepsea cat shark", "Greenland shark", 
  "Jensen's skate", "Little skate", "Manta", "Ocean quahog", "Oceanic whitetip shark", 
  "Porbeagle", "Portuguese shark", "Rough sagre", "Roughtail stingray", 
  "Round skate", "Sharks", "Shortfin mako", "Skates", "Smooth skate", 
  "Soft skate", "Spiny dogfish", "Spinytail skate", "Thorny skate", 
  "White shark", "White skate", "Winter skate", "NA"), class = "factor"), 
      elasmo.discard = c(1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 0, 
      25, 0, 0, 0, 1, 0, 0, 1, 1, 15, 25)), .Names = c("EID", "tspp.name", 
  "elasmo.name", "elasmo.discard"), class = "data.frame", row.names = c("18496", 
  "488791", "87549", "236671", "139268", "15606", "11132", "115531", 
  "93441", "159675", "403751", "42587", "485941", "19285", "130395", 
  "119974", "73826", "7953", "99124", "351461", "71", "72", "184", 
  "185"))

n <- nrow(sample)
N <- 145349
p <- ceiling(log2(N / n))
n * 2^p
n * 2^p > N

# Bad way of increasing the row number
for (i in 1:p) sample <- rbind(sample, sample)

nrow(sample)

class(sample)
head(sample)

table(sample$elasmo.name)
table(as.character(sample$elasmo.name))

test <- dcast(sample, ... ~ elasmo.name,
              value.var = "elasmo.discard",
              fun.aggregate = sum)
head(test)

【讨论】：

嗯...有趣的@djhurio。我将对此进行更多研究。不知道出了什么问题！