Question

我有600多个数据帧的列表，这些数据帧没有相同的确切变量类型。有时，该类与所需的类有所不同，例如，在整数之前有一个字母，这使整个列成为一个字符（只是因为一个愚蠢的错字...）我需要做的是确定这些数据框没有所需的变量类并进行修改，因此我可以将所有数据用于不同目的（汇总，分析等）。（我要求类似的帮助，但要注意How to split a list of data frames based on its column names?此处的列名）

我试图根据所需的变量顺序和类别从主列表创建两个列表。为此，我尝试执行以下操作：

v1 <- c(1:15)
v2 <- c(20:34)
v3 <- c("a","b","c","d","e","f","g","h","i","j","k","l","m","n","o")
v3b <- c("a","b","c","d","e","f","g","h","i","j","k","l","m","n","o")

df1 <- data.frame(v1, v2, v3)
df2 <- data.frame(v1, v2, v3)
df3 <- data.frame(v1, v2, v3b)

df1[1,2] <- "m3" 

mylist <- list(df1, df2, df3)

str(mylist[[1]]) # here you can see the class of each variable and how in df1 the class has been changed from integer to character
d_class <- sapply(mylist[[2]], class) # this is how I get the desired class

# now I try to alternatives to identify the dfs with the undesired structure:
#1
list_a <- list()
list_a <- lapply(mylist, function(x) class(x) == d_class) # do not work
grep('FALSE', list_a)

#2
list_b <- list()
list_b <- split(mylist,sapply(mylist,function(x) 
identical(class(x),d_class)))

您可以看到，我总是得到所有的数据帧作为返回，并且即使先前指定了代码，代码也无法识别所需的类。

有人知道这段代码有什么问题吗？

非常感谢您的帮助

Answer 1

由于它是RPS1='%F{154}%D{%H}%F{155}:%F{156}%D{%M}%F{157}:%F{158}%D{%S}'中的list，所以data.frame是class。我们需要遍历数据集以获得单个列的类

data.frame

如果我们需要逻辑索引lapply(mylist, function(x) sapply(x, class) == d_class)来查找与'd_class'中具有相同vector的那些数据集，请在逻辑向量上用class包装

all

如何根据变量的类别拆分数据帧列表？

1 个答案: