CONTRAST Subcommand (GLM command)

When the CONTRAST subcommand is used, an L matrix, which is used in custom hypothesis testing, is generated according to the chosen contrast. The K matrix is always taken to be the zero matrix. If the model is univariate or multivariate, the M matrix is always the identity matrix, and its dimension is equal to the number of dependent variables. For a repeated measures model, the M matrix is always the average matrix that corresponds to the average transformation for the dependent variable.

See the topic CONTRAST Subcommand (GLM: Univariate command) for more information.