For matrices, mean (X) is a row vector containing the mean value of each column.

对于矩阵来说，MEAN (X)是包含了每列平均值的行向量。

youdao

One thing that can be confusing about R's "everything is a vector" approach is that row-wise and column-wise operations may not adhere to your intuition.

关于 R 的 “所有东西都是向量” 方式，容易引起混乱的一点是行操作和列操作可能不符合直觉。

youdao

But if you wanted to create a vector to sum each row, you might be inclined to try the following.

但是，如果希望创建一个向量来求每行的总和，您可能会编写下面这样的代码。

youdao