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我正在使用 lme4 附带的数据集，并且正在尝试学习如何应用 reshape2 将其从长转换为宽 [帖子末尾的完整代码]。 

library(lme4)
data("VerbAgg")  # load the dataset

数据集有 9 个变量；“Anger”、“Gender”和“id”不随“item”而变化，而“resp”、“btype”、“situ”、“mode”和“r2”则不同。

我已经成功地使用 reshape() 将数据集从长格式转换为宽格式：

wide <- reshape(VerbAgg, timevar=c("item"), 
             idvar=c("id", 'Gender', 'Anger'), dir="wide")

这产生了对 123 个变量的 316 个观测值，并且似乎已正确转换。但是，我没有成功使用 reshape/reshape2 来重现宽数据框。

wide2 <- recast(VerbAgg, id + Gender + Anger ~ item + variable)
Using Gender, item, resp, id, btype, situ, mode, r2 as id variables
Error: Casting formula contains variables not found in molten data: Anger

我可能不是 100% 清楚 recast 如何定义 id 变量，但我很困惑为什么它没有看到“愤怒”。相似地，

wide3 <- recast(VerbAgg, id + Gender + Anger ~ item + variable, 
               id.var = c("id", "Gender", "Anger"))
Error: Casting formula contains variables not found in molten data: item

谁能看到我做错了什么？我很想更好地了解熔化/铸造！

完整代码：

## load the lme4 package 
library(lme4) 
data("VerbAgg")
head(VerbAgg)
names(VerbAgg) 

# Using base reshape()
wide <- reshape(VerbAgg, timevar=c("item"), 
                 idvar=c("id", 'Gender', 'Anger'), dir="wide")

# Using recast
library(reshape2)
wide2 <- recast(VerbAgg, id + Gender + Anger ~ item + variable)
wide3 <- recast(VerbAgg, id + Gender + Anger ~ item + variable, 
                id.var = c("id", "Gender", "Anger"))

# Using melt/cast
m <- melt(VerbAgg, id=c("id", "Gender", "Anger"))
wide <- o cast(m,id+Gender+Anger~...)
Aggregation requires fun.aggregate: length used as default
# Yields a list object with a length of 8? 

m <- melt(VerbAgg, id=c("id", "Gender", "Anger"), measure.vars = c(4,6,7,8,9))
wide <- dcast(m, id ~ variable)
# Yields a data frame object with 6 variables.
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1 回答 1

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我认为以下代码可以满足您的要求。

library(lme4) 
data("VerbAgg")

# Using base reshape()
wide <- reshape(VerbAgg, timevar=c("item"), 
                 idvar=c("id", 'Gender', 'Anger'), dir="wide")
dim(wide) # 316 123

# Using melt/cast
require(reshape2)
m1 <- melt(VerbAgg, id=c("id", "Gender", "Anger","item"), measure=c('resp','btype','situ','mode','r2'))
wide4 <- dcast(m1,id+Gender+Anger~item+variable)
dim(wide4) # 316 123

R> wide[1:5,1:6]
  Anger Gender id resp.S1WantCurse btype.S1WantCurse situ.S1WantCurse
1    20      M  1               no             curse            other
2    11      M  2               no             curse            other
3    17      F  3          perhaps             curse            other
4    21      F  4          perhaps             curse            other
5    17      F  5          perhaps             curse            other

R> wide4[1:5,1:6]
  id Gender Anger S1WantCurse_resp S1WantCurse_btype S1WantCurse_situ
1  1      M    20               no             curse            other
2  2      M    11               no             curse            other
3  3      F    17          perhaps             curse            other
4  4      F    21          perhaps             curse            other
5  5      F    17          perhaps             curse            other
于 2012-11-28T14:56:16.233 回答