WOMBAT provides limited facilities to fix certain covariance components at their input values, while maximising the (log) likelihood with respect to the remaining parameters. Again, this information is given in a block entry. The block begins with a line containing the code FIXVAR (no abbreviation) and, as usual, ends with a line containing the code END. Each line within the block is then expected to have the following entries:
In the moment, no options to fix individual elements of covariance matrices are recognised.