Contributing to the Data Repo

Preliminary Guide for Contributing to the Data Repo.

Please also refer to our contributing constitution

Adding a Problem-Method-Solution tuple

Note: Every entity type (ProblemSpecification, ProblemSolution, MethodPackage) makes sense of its own, e.g. adding a new solution for an already existing problem. However, in many cases it is meaningful to add all three of them.

  • Preparation:

  • Integration of new data:

    • New ProblemSpecification:

      • Create a new subdirectory: like ackrep_data/problem_specifications/<your_problem>.

      • Copy your problem-specification-file into the directory and change name to

      • Generate a new random key: ackrep --key.

      • Copy the file metadata.yml from an existing entity of the same type and change its content beginning with the new key.

      • Ensure that the function evaluate_solution returns an instance of ackrep_core.ResultContainer, see existing examples.

    • New MethodPackage:

      • Create a new subdirectory: like ackrep_data/method_packages/<your_method>/src.

      • Copy your code into that directory.

      • Generate a new random key: ackrep --key.

      • Copy the file metadata.yml from an existing entity of the same type to ackrep_data/method_packages/<your_method> and change its content beginning with the new key.

    • New ProblemSolution:

      • Create a new subdirectory: like ackrep_data/problem_solutions/<your_problem_solution>.

      • Copy your problem-solution-file into the directory and change name to

      • Generate a new random key: ackrep --key.

      • Copy the file metadata.yml from an existing entity of the same type and change its content beginning with the new key.

      • Add all keys of solved problems and dependent method packages.

  • Evaluate solution:

    • Change working directory to ackrep_data.

    • Run ackrep --load-repo-to-db . in that directory.

    • Check a specific solution via ackrep --check problem_solutions/<your_problem_solution>/metadata.yml.

    • If an error occurs:

      • Manually run python and see the error messages.

      • Common issues:

        • Forgot to run ackrep --load-repo-to-db . after changing metadata.

        • ImportError due to missing package in the python_path (see what actually is inserted); Probable cause: missing or wrong key in metadata.yml

        • Bad return-value of evaluate_solution

Adding a System Model

Directory for a new system model: ackrep_data/system_models/<model_name>/

  1. Copy the _template-folder. Rename it in the following way: <model_name>_system

  2. Generate a new key with ackrep --key

  3. Edit metadata.yml

    • insert the generated key

    • add a name, short description and suitable tags

    • fill in your full name and email in the creator space

       creator: 'Max Musterman <max.musterman{ät}>'
    • add the creation date like 2022-04-21

    • insert the estimated runtime of the simulation such as 10s

  4. Edit

    • adjust def initialize(self)

      • define the number of inputs self.u_dim

      • define the system dimension self.sys_dim

      • in case your model is an n extendable system:

        • see example n_integrator_chain_system (Key: CAS0M)

        • remove self.sys_dim, you don’t have to define it

        • define self.default_param_sys_dim for the simulation, this dimension should suit the dimension of the example in your parameter file

    • adjust def uu_default_function(self)

      • in case your model doesn’t need any input function, you can delete this whole function. Otherwise:

      • create symbolic input functions

      • transform symbolic to numeric function via st.expr_to_func()

      • adjust def uu_rhs(t. xx_nv)

        • create the numerical values

        • return inputs wrapped by a list

    • adjust def get_rhs_symbolic(self)

      • get the symbolic state components, parameters and inputs

      • define the symbolic functions

      • return the functions wrapped by a list

  5. Edit

    • in case your model doesn’t need any parameters, just leave a comment like #This model does not need any parameters. and delete everything else. Otherwise:

    • create the symbolic parameters such as

      pp_symb = [l, g, a, omega, gamma] = sp.symbols('l, g, a, omega, gamma', real=True)
    • OPTIONAL: You can define a range your parameters. This range appears in the pdf. If a parameters is chose outside its designated range, a warning is issued.


      Right now, you can only define a parameter range for all parameters or for none.

      You have to provide the variable pp_range_list as a list of the same length as pp_symb. pp_range_list has to contain a range object for each parameter in the same order as they appear in pp_symb. Valid values for pp_range_list are:

      Information to be expressed


      open Intervall (a,b) (use np.inf to represent infinity)

      list (a,b)

      closed intervall [a,b]

      list [a,b]

      number field (e.g. Z)

      str “Z”

      parameter is constant/ parameter shall not be changed


    • you can define auxiliary symbolic parameters, which should not be numerically represented in the parameter table

    • define symbolic parameter functions and add them to the list pp_sf

    • fill in the list for substitution; if you don’t need it leave the list empty. Don’t delete it.

    • define the LaTeX table

      • the table always contains the two columns Symbol and Value. You can add additional columns before and afte these, for example Parameter Name or Unit

      • define for each new column the entries in a list

      • when it is about a column before the fixed ones, add it to the list start_columns_list, if not add it to end_columns_list

      • for example:

      tabular_header = ["Parameter Name", "Symbol", "Value", "Unit"]
      col_alignment = ["left", "center", "left", "center"]
      col_1 = ["acceleration due to gravity", 
              "distance of forces to mass center",
              "moment of inertia"
      start_columns_list = [col_1]
      col_4 = [r"$\frac{\mathrm{m}}{\mathrm{s}^2}$", 
              r"$\mathrm{kg} \cdot \mathrm{m}^2$"
      end_columns_list = [col_4]
      • the result in LaTeX:

  6. Edit

    • adjust def simulate()

      • define initial state values xx0, simulation time tend and vector of times for simulation tt

      • in case you don’t want to define an inputfunction, which is different to the uu_default_function remove uu = and simulation_data.uu = . The uu_default_function is automatically used as inputfunction. Otherwise:

      • define inputfunction uu

    • adjust def save_plot()

      • plot the relevant and representing data of your model here

      • if you want to create multiple plots, either use subplots or create them separately and always call save_plot_in_dir(<plot_name>.png) after each plot. Make sure to chose unique names. Plots will appear in alphanumeric order.

    • adjust def evaluate_simulation(simulation_data)

      • fill in the expected_final_states of your model to check whether everything is working out

  7. Go to _system_model_data

    • adjust documentation.tex

      • update the headline with your system model name

      • explain parameters, inputs and state components in the subsection Nomenclature for Model Equations

        • in contrast to the parameter table, here you can explain the parameters in more detail

        • the table is intended for a quick overview of the parameters and is automatically build based on

      • define state vectors, input vectors and system equations

      • list parameters and outputs; if they don’t exist just fill in <not defined>

      • specify the assumptions underlying this model (e.g. neglected fast subsystems, valid ranges of system quantities)

      • optionally fill out the section Derivation and Explanation (how was the model derived, what is important to know)

      • add your references

  8. Update the parameters.tex via ackrep --update-parameter-tex <key>

  9. Create the documentation.pdf via ackrep --create-pdf <key>

  10. Test your model locally:

    • ackrep -csm <key> = ackrep --check-system-model <key>