FVCOVARIANCE procedure

Forms the variance-covariance matrix for a list of variates (W. van den Berg).


Options

PRINT = strings
Printed output (df, vcovariance); default df, vcov

WEIGHTS = variate                           Provides weights for the units of the variates; default * assumes that they all have weight one

VCOVARIANCE = symmetric matrix
Saves the variance-covariance matrix

DF = scalar
Saves the number of degrees of freedom of the (co)variances


Parameter

DATA = variates
Variates for which the matrix is to be calculated


Description

FVCOVARIANCE calculates vcovariance matrices for a set of variates which should be listed by the DATA parameter. The WEIGHTS option can provide a variate of weights for the units of the variates; by default these are all assumed to have weight one. The vcovariance matrix can be saved using the VCOVARIANCES option, and the degrees of freedom can be saved using DF option.

   Printed output is controlled by the PRINT option with settings:

    vcovariance
prints the variance-covariance matrix,

    df
prints the degrees of freedom.

By default both are printed.

 

Options: PRINT, WEIGHTS, VCOVARIANCES, DF.

Parameter: DATA.


Method

A SSPM structure is set up for the DATA variates, and its values are formed using the FSSPM directive. The corrected sums of squares and products are divided by the residual degrees of freedom to give the variance covariance matrix.


Action with RESTRICT

FVCOVARIANCE takes account of restrictions on any of the variates.