Question

dput(x)
structure(c("2005-01-01:  1  ", "2005-01-02:  1  ", "2005-01-03:  1  ", 
"2005-01-04:  1  ", "2005-01-05:  1  ", "2005-01-06:  1  ", "(Other)   :724  ", 
"Min.   :  1.700  ", "1st Qu.:  3.062  ", "Median :  4.345  ", 
"Mean   :  6.267  ", "3rd Qu.:  7.435  ", "Max.   : 22.100  ", 
"NA's   :666.000  ", "Min.   :  0.2490  ", "1st Qu.:  0.6182  ", 
"Median :  1.0500  ", "Mean   :  2.2679  ", "3rd Qu.:  2.7825  ", 
"Max.   : 10.8000  ", "NA's   :666.0000  ", "Min.   :101  ", 
"1st Qu.:101  ", "Median :101  ", "Mean   :101  ", "3rd Qu.:101  ", 
"Max.   :101  ", NA), .Dim = c(7L, 4L), .Dimnames = list(c("", 
"", "", "", "", "", ""), c("Dat", "Var1", "Var2", "Name")), class = "table")

我想看看这个：

x$Var1

并收到此错误：

Error in x$Var1 : $ operator is invalid for atomic vectors

任何想法，我在做什么都错了？

Answer 1

我在这里稍微阅读一下这些行，但为了获得每个变量所需的数据类型，你可能最好做一些像：

# create some test data
> test <- data.frame(Dat=1:10,Var1=1:10)
> result <- lapply(test,summary)
> result
$Dat
   Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
   1.00    3.25    5.50    5.50    7.75   10.00 

$Var1
   Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
   1.00    3.25    5.50    5.50    7.75   10.00

允许你这样做：

> result$Var1
   Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
   1.00    3.25    5.50    5.50    7.75   10.00

Answer 2

这有效：

> x[,'Var1']

"Min.   :  1.700  " "1st Qu.:  3.062  " "Median :  4.345  " "Mean   :  6.267  " "3rd Qu.:  7.435  " 

"Max.   : 22.100  " "NA's   :666.000  "

一个简单的例子：

y <- rep(letters[1:3], each=10)
table(y)
## y
##  a  b  c 
## 10 10 10 

table(y)$a
## Error in table(y)$a : $ operator is invalid for atomic vectors

Answer 3

马修正在给你误导性建议，而不是R是误导你的实体。错误信息是准确的，如果您注意，那么您可以学习有价值的课程。 R表真的是矩阵。它们从is.matrix返回TRUE，所有常用的访问方法都有效。 $运算符用于列表（其中'dataframe'是子类...但'matrix'不是。）请注意，他为您提供了一种访问方法，该方法使用了矩阵响应命名维度的访问这一事实指数。

无法读取摘要功能中的列

3 个答案: