range (Statistics Toolbox)

Sample range.

Syntax

y = range(X)

Description

range(X) returns the difference between the maximum and the minimum of a sample. For vectors, range(x) is the range of the elements. For matrices, range(X) is a row vector containing the range of each column of X.

The range is an easily calculated estimate of the spread of a sample. Outliers have an undue influence on this statistic, which makes it an unreliable estimator.

Example

The range of a large sample of standard normal random numbers is approximately six. This is the motivation for the process capability indices C_p and C_pk in statistical quality control applications.

rv = normrnd(0,1,1000,5);
near6 = range(rv)

near6 =

    6.1451    6.4986    6.2909    5.8894    7.0002