stdevf

Arguments

x

real or complex vector or matrix

fre

real or complex vector or matrix

orientation

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

• a character "*" (default), "r" or "c"
• a positive integer: 1 or 2. 1 is equivalent to "r" and 2 is equivalent to "c".

s

real or complex scalar or vector

Description

This function computes the standard deviation of the values of a vector or matrix x, each of them counted with a frequency given by the corresponding values of the integer vector or matrix fre who has the same type of x.

For a vector or matrix x, s = stdevf(x,fre) (or s = stdevf(x,fre,'*') returns in scalar s the standard deviation of all the entries of x, each value counted with the multiplicity indicated by the corresponding value of fre.

s = stdevf(x,fre,'r') (or, equivalently, s = stdevf(x,fre,1)) returns in each entry of the row vector s of type 1xsize(x,'c') the standard deviation of each column of x, each value counted with the multiplicity indicated by the corresponding value of fre.

s = stdevf(x,fre,'c') (or, equivalently, s = stdevf(x,fre,2)) returns in each entry of the column vector s of type size(x,'c')x1 the standard deviation of each row of x, each value counted with the multiplicity indicated by the corresponding value of fre.

Examples

x=[0.2113249 0.0002211 0.6653811;0.7560439 0.9546254 0.6283918]
fre=[1 2 3;3 4 3]
m=stdevf(x,fre)
m=stdevf(x,fre,'r')
m=stdevf(x,fre,'c')

Bibliography

Wonacott, T.H. & Wonacott, R.J.; Introductory Statistics, fifth edition, J.Wiley & Sons, 1990.