我应该使用 data.frame 还是矩阵? [英] Should I use a data.frame or a matrix?

问题描述

什么时候应该使用data.frame，什么时候使用matrix更好?

When should one use a data.frame, and when is it better to use a matrix?

两者都以矩形格式保存数据，因此有时不清楚.

Both keep data in a rectangular format, so sometimes it's unclear.

是否有关于何时使用哪种数据类型的一般经验法则?

Are there any general rules of thumb for when to use which data type?

推荐答案

部分答案已包含在您的问题中:如果列(变量)可以预期为不同类型(数字/字符/逻辑等).矩阵用于相同类型的数据.

Part of the answer is contained already in your question: You use data frames if columns (variables) can be expected to be of different types (numeric/character/logical etc.). Matrices are for data of the same type.

因此，只有当您拥有相同类型的数据时，选择 matrix/data.frame 才会有问题.

Consequently, the choice matrix/data.frame is only problematic if you have data of the same type.

答案取决于您将如何处理 data.frame/matrix 中的数据.如果要将其传递给其他函数，则这些函数的参数的预期类型决定了选择.

The answer depends on what you are going to do with the data in data.frame/matrix. If it is going to be passed to other functions then the expected type of the arguments of these functions determine the choice.

还有:

矩阵的内存效率更高:

m = matrix(1:4, 2, 2)
d = as.data.frame(m)
object.size(m)
# 216 bytes
object.size(d)
# 792 bytes

如果您打算进行任何线性代数类型的运算，矩阵是必不可少的.

Matrices are a necessity if you plan to do any linear algebra-type of operations.

如果您经常按名称(通过紧凑的 $ 运算符)引用其列，则数据框会更方便.

Data frames are more convenient if you frequently refer to its columns by name (via the compact $ operator).

恕我直言，数据框也更适合报告(打印)表格信息，因为您可以分别对每一列应用格式.

Data frames are also IMHO better for reporting (printing) tabular information as you can apply formatting to each column separately.

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