变量的无效类型(列表) [英] invalid type (list) for variable

问题描述

我正在尝试在 R 中运行 anova 模型.我有一个包含 3 行 12 列的数据文件.每行是解释变量特定级别的数据.单元格 [i,j] 是水平 i 的第 j 个响应.该文件是.dat"扩展名.我正在运行以下 R 代码以尝试获取 36 x 2 数据帧来运行 anova 模型而不是 3 x 12 原始数据帧:

I am trying to run an anova model in R. I have a data file which contains 3 rows and 12 columns. Each row is data for a particular level of the explanatory variable. Cell [i,j] is the j'th response for level i. The file is ".dat" extension. I am running the following R code to try to get a 36 by 2 data frame to run the anova model instead of the 3 by 12 original data frame:

data <- read.table("usedcar.dat", row.names = 1)
young <- data[1,]
med <- data[2,]
old <- data[3,]
Price <- c(young, med, old)
Age <- as.factor(c(rep(1,12), rep(2,12), rep(3,12)))
data <- cbind(Age, Price)
data <- as.data.frame(data)

但是当我尝试从中获取 anova 模型时，我收到了无效列表类型错误:

But when I try to get the anova model out of it I get the invalid list type error:

m1 <- aov(Price ~ Age, data = data)
Error in model.frame.default(formula = Price ~ Age, data = data, drop.unused.levels = TRUE) : invalid type (list) for variable 'Price'

我在这里做错了什么?

这是一个随机矩阵，如果有帮助的话:

Here's a random matrix if that will help:

replicate(12, rnorm(3))

这里是 str(data) 结果:

Here is the str(data) result:

str(data)
'data.frame':   36 obs. of  2 variables:
 $ Age  :List of 36
  ..$ 1 : int 1
  ..$ 2 : int 1
  ..$ 3 : int 1
  ...
  ..$ 36: int 3
 $ Price:List of 36
  ..$ 1 : int 2300
  ...
  ..$ 36: int 2075

推荐答案

tl;dr 数据框的行是列表，而不是数字向量.当您 read.table() 时，您会得到一个数据框(因此，像我之前所做的那样，构建矩阵不会复制问题).

tl;dr rows of data frames are lists, not numeric vectors. When you read.table() you get a data frame (so constructing a matrix, as I did before, doesn't replicate the problem).

data <- as.data.frame(matrix(rnorm(36),nrow=3))
young <- data[1,]; med <- data[2,]; old <- data[3,]
Price <- c(young, med, old)
str(Price)
## ## List of 36
## ##  $ V1 : num 0.648
## ##  $ V2 : num 0.157
## ## ...

事实上这是一个列表，而不是一个数字向量，这是一个问题.有多种处理方法.最简单的是unlist():

The fact that this is a list, not a numeric vector, is a problem. There are a variety of ways of handling this. The easiest is unlist():

dd <- data.frame(Age,Price=unlist(Price))
aov(Price~Age,dd)

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