Parameters

Description

This function computes the F ratio for samples of unequal size.

"The most efficient design is to make all samples the same size n. However when this is nor feasible, it still is possible to modify the ANOVA calculations." Note that the definition of xbarbar is no longer mean(xbar), but rather a weighted average with weights ni. Additionnally it gives (in p) the p-value of the computed Fischer ratio.

Given a number a of samples each of them composed of n_i (i from 1 to a) observations this fonction computes in f the Fischer ratio (it is the ratio between nr times the variance of the means of samples and the mean of the variances of each sample).

f=ftest(samples) computes the Fischer ratio of the nc samples whose values are in the columns of the matrix samples. Each one of these samples is composed of nr values. (The Fischer ratio is the ratio between nr times the variance of the means of samples and the mean of variances of each sample)

[f,p]=ftest(samples) gives in p the p-value of the computed Fischer ratio f.

References

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

Examples

samples=[46 55 54;53 54 50; 49 58 51;50 61 51;46 52 49]
[f,p]=ftest(samples)
 
  

See also

Author

Carlos Klimann