如何获得平均数，中位数，和其他在整个矩阵，数组或数据帧的统计数据？ [英] How to get mean, median, and other statistics over entire matrix, array or dataframe?

问题描述

我知道这是一个基本的问题，但由于某种奇怪的原因，我无法找到答案。

I know this is a basic question but for some strange reason I am unable to find an answer.

我应该如何运用基本的统计功能，如平均值，中位数等在整个阵列，矩阵或数据框获得独特的答案，而不是过度的行或列向量

How should I apply basic statistical functions like mean, median, etc. over entire array, matrix or dataframe to get unique answers and not a vector over rows or columns

推荐答案

由于这来了一个公平一点，我打算把这个多一点COM prehensively，包括了等等。片中除了平均值和中位数。

Since this comes up a fair bit, I'm going to treat this a little more comprehensively, to include the 'etc.' piece in addition to mean and median.

1. 对于一个矩阵或数组，因为其他人说，的意思是和中位数将返回单个值。然而， VAR 将计算二维矩阵的列之间的协方差。有趣的是，对于一个多维阵列，无功追溯到返回一个值。 SD 上的2-D矩阵将工作，但pcated德$ P $，返回列的标准偏差。更妙的是，狂返回上一个二维矩阵的和的多维数组的单个值。如果你的希望的一个返回值，最安全的方法是使用 as.vector（）第一要挟。高兴了吗？

1. For a matrix, or array, as the others have stated, mean and median will return a single value. However, var will compute the covariances between the columns of a two dimensional matrix. Interestingly, for a multi-dimensional array, var goes back to returning a single value. sd on a 2-d matrix will work, but is deprecated, returning the standard deviation of the columns. Even better, mad returns a single value on a 2-d matrix and a multi-dimensional array. If you want a single value returned, the safest route is to coerce using as.vector() first. Having fun yet?

对于 data.frame ，的意思是是德precated，但会再次采取行动上单独的列。 中位数要求您强制为向量第一，或不公开。和以前一样， VAR 将返回协方差和 SD 又是pcated德$ P $，但将返回标准偏差的列。 狂要求您强制为向量或不公开。一般来说一个 data.frame 如果你想要采取行动的所有值，你通常只会不公开首先

For a data.frame, mean is deprecated, but will again act on the columns separately. median requires that you coerce to a vector first, or unlist. As before, var will return the covariances, and sd is again deprecated but will return the standard deviation of the columns. mad requires that you coerce to a vector or unlist. In general for a data.frame if you want something to act on all values, you generally will just unlist it first.

编辑：最新新闻（）：就R 3.0.0 mean.data.frame是defunctified：

Late breaking news(): In R 3.0.0 mean.data.frame is defunctified:

o   mean() for data frames and sd() for data frames and matrices are
defunct.

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