iqr

Arguments

x

real or complex vector or matrix

orientation

index of the dimension along which the iqr is computed. It can be either

• a character "*" (default), "r", "c" or "m". "m" is equivalent to find(size(x)>1,1).
• a positive integer. 1 is equivalent to "r" and 2 is equivalent to "c".

q

real or complex scalar or vector

Description

This function computes the interquartile range IQR= upper quartile - lower quartile of a vector or a matrix x.

For a vector or a matrix x , q=iqr(x) or q=iqr(x, "*") returns in the scalar q the interquartile range of all the entries of x.

q=iqr(x,'r') (or, equivalently, q=iqr(x,1)) is the rowwise interquartile range. It returns in each entry of the row vector q the interquartile range of each column of x.

q=iqr(x,'c') (or, equivalently, q=iqr(x,2)) is the columnwise interquartile range. It returns in each entry of the column vector q the interquartile range of each row of x.

Examples

x  = 1:10;

// Interquartile range of vector 1 to 10
// Q1 = 3 and Q3 = 8, so iqr = 5
iqr(x)

Bibliography

Wonacott, T.H.Wonacott, R.J.; Introductory Statistics, J.Wiley-Sons, 1990.