r - Octave/Matlab 中的scale() R 函数等效项

Question

为了避免循环，有没有一种方法可以将数据矩阵围绕列(或行)的平均值居中，并按标准差(也可以按列或按行)缩放每个条目？

在 R 中这很简单:scale(data, center = T,scale = T))。

但我不知道如何在 Ocatave 或 Matlab 中实现相同的基本预处理。

Answer 1

在 Octave 中，有两个函数分别用于 center() 和 zscore()。 center 只是减去平均值，而 zscore 还除以 sd(有时称为标准化的操作)

center (x)

Center data by subtracting its mean.

If x is a vector, subtract its mean. If x is a matrix, do the above for each column. If the optional argument dim is given, operate along this dimension.

和

zscore (x, opt, dim) Computes the Z score of x

if x is a vector, subtract its mean and divide by its standard deviation. If the standard deviation is zero, divide by 1 instead.

The optional parameter opt determines the normalization to use when computing the standard deviation and has the same definition as the corresponding parameter for std.

If x is a matrix, calculate along the first non-singleton dimension. If the third optional argument dim is given, operate along this dimension.