SAS for Mixed Models, Second Edition, 2nd Edition

Heterogeneous Variance Models

9

9.1 Introduction

9.2 Example: Two-Way Analysis of Variance with Unequal Variances

9.2.1 Testing for Homogeneity of Variances

9.2.2 Fitting a Model with Heterogeneous Variances

9.2.3 Fitting a Model with Reduced Heterogeneous Variance Structure

9.3 Example: Simple Linear Regression Model with Unequal Variances

9.3.1 Fit Power-of-X Model Using REML

9.3.2 Fit Power-of-X Model Using ML

9.3.3 Fit Power-of-X Model Using ML from PROC NLMIXED

9.3.4 Fit Power-of-the-Mean Model Using REML

9.3.5 Fit Power-of-the-Mean Model Using ML from PROC MIXED

9.3.6 Fit Power-of-the-Mean Model Using ML from PROC NLMIXED

9.3.7 Comparison of Power-of-X and Power-of-the-Mean Model Covariance Structures

9.4 Example: Nested Model with ...