Design matrix

The DESIGN_MATRIX keyword in ERT allows users to define a design matrix in Excel, as described in the DESIGN_MATRIX section of the documentation. The design matrix contains parameters and their values per realization.

DESIGN2PARAMS is a deprecated forward model and users are encouraged to migrate to the DESIGN_MATRIX keyword for defining design matrices. The DESIGN_MATRIX keyword accepts the same parameters as DESIGN2PARAMS.

If the same parameter name is defined both in the design matrix and in the GEN_KW parameter definition, the value from the design matrix takes precedence and the parameter will not be updated by ERT.

Migration from DESIGN2PARAMS

Migrating from the DESIGN2PARAMS forward model involves updating your configuration to use the DESIGN_MATRIX keyword. The DESIGN_MATRIX keyword replaces DESIGN2PARAMS by integrating design matrix functionality directly into ERT, offering improved validation and parameter usability (like plotting) in ERT.

To migrate, replace instances of DESIGN2PARAMS in your configuration file with DESIGN_MATRIX:

For example

FORWARD_MODEL DESIGN2PARAMS(<xls_filename>=<CONFIG_PATH>/<DESIGN_MATRIX>, <designsheet>=<DESIGN_SHEET>, <defaultssheet>=DefaultValues)

should be replaced with DESIGN_MATRIX as follows:

DESIGN_MATRIX <CONFIG_PATH>/<DESIGN_MATRIX> DESIGN_SHEET:<DESIGN_SHEET> DEFAULT_SHEET:DefaultValues

Additionally, review the documentation for DESIGN_MATRIX.

NOTE: The DESIGN_MATRIX validation is more strict than that of DESIGN2PARAMS. Some problems that were previously hidden or resulting in failures during runtime, will now result in errors during validation of the configuration:

• Missing values (empty cells) in the design matrix

• Duplicate parameter names in the design matrix

• Design sheet is empty

• REAL column must only contain unique, positive integers