# BLUPF90

### Site Tools

how_to_estimate_different_residual_co_variances_by_class_in_airemlf90_as_in_gibbs3f90

Basic idea is: to specify dummy covariates (“0” or “1”) in the “hetres_pos” option.

In this example, we will consider 3 different residual variances by class in a single-trait model. We need extra 3 columns in the data file. Each column contains the following information:

extra column 1: "1" if this observation is related to the residual variance 1; else "0".
extra column 2: "1" if this observation is related to the residual variance 2; else "0".
extra column 3: "1" if this observation is related to the residual variance 3; else "0".

We assume these columns are corresponding to 6-th, 7-th, and 8-th columns in the data file, respectively.

OPTION hetres_pos 6 7 8
OPTION hetres_pol 20.0 20.0 20.0