Adding new Options

Default options are set by the class Options, which is defined in the file fitbenchmarking/utils/

The options used can be changed using an .ini formatted file (see here). FitBenchmarking Options gives examples of how this is currently implemented in FitBenchmarking.

To add a new option to one of the five sections FITTING, MINIMIZERS, JACOBIAN, OUTPUT and LOGGING, follow the steps below. We’ll illustrate the steps using <SECTION>, which could be any of the sections above.

  1. Amend the dictionary DEFAULT_<SECTION> in Options to include any new default options.

  2. If the option amended is to be checked for validity, add accepted option values to the VALID_<SECTION> dictionary in Options.

  3. Using the read_value() function, add your new option to the class, following the examples already in Options. The syntax of this function is:

    Options.read_value(func, option, additional_options)

    Helper function which loads in the value

    • func (callable) – configparser function

    • option (str) – option to be read for file

    • additional_options – A dictionary of options

    input by the user into the command line. :type additional_options: dict


    value of the option

    Return type


  4. Add tests in the following way:

    • Each of the sections has it’s own test file, for example, test_option_fitting has tests for the FITTING section.

    • Add default tests to the class called <SECTION>OptionTests.

    • Add user defined tests to the class called User<SECTION>OptionTests. These should check that the user added option is valid and raise an OptionsError if not.

  5. Add relevant documentation for the new option in FitBenchmarking Options.

Adding new Sections is also possible. To do this you’ll need to extend VALID_SECTIONS with the new section, and follow the same structure as the other SECTIONS.