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The '''madc''' function is a scale estimator given by the Median Absolute Deviation (with finite sample correction factor). | The '''madc''' function is a scale estimator given by the Median Absolute Deviation (with finite sample correction factor). | ||
It is defined as: | It is defined as: | ||
madc(x)= b_n 1.4826 med(|x_i - med(x)|) | |||
with <code>b_n</code> a small sample correction factor to make the mad unbiased at the normal distribution. It can resist 50% outliers. If <code>x</code> is a matrix, the scale estimate is computed on the columns of <code>x</code>. The result is then a row vector. If <code>x</code> is a row or a column vector, the output is a scalar. | with <code>b_n</code> a small sample correction factor to make the mad unbiased at the normal distribution. It can resist 50% outliers. If <code>x</code> is a matrix, the scale estimate is computed on the columns of <code>x</code>. The result is then a row vector. If <code>x</code> is a row or a column vector, the output is a scalar. | ||
Latest revision as of 10:48, 5 December 2019
Description
The madc function is a scale estimator given by the Median Absolute Deviation (with finite sample correction factor). It is defined as:
madc(x)= b_n 1.4826 med(|x_i - med(x)|)
with b_n a small sample correction factor to make the mad unbiased at the normal distribution. It can resist 50% outliers. If x is a matrix, the scale estimate is computed on the columns of x. The result is then a row vector. If x is a row or a column vector, the output is a scalar.
This function is part of LIBRA: the Matlab Library for Robust Analysis, available at:
http://wis.kuleuven.be/stat/robust.html
Written by S.Verboven
Synopsis
result = madc(x);
Inputs
- x either a data matrix with n observations in rows, p variables in columns or a column vector of length n.