(calibration_minimisation)=
# Minimisation techniques

```{warning}
This method is entirely reliant on the **Relauncher** architecture so the only available 
constructor is the runner constructor (discussed in the section [](#calibration_classes_functions_observations_calibration_classes_runner)). 
This means there is no constructor based on `TCode` or function (respectively described in 
[](#calibration_classes_functions_observations_calibration_classes_tcode) and 
[](#calibration_classes_functions_observations_calibration_classes_function_launcher_archi)). This is 
because the method uses the **Nlopt**-algorithm library, introduced in [](#reoptimizer_module) 
or the **Vizir** package for multi-criteria and many-objective algorithms.
```

Even though the theory behind this method is not revolutionary, these methods are of interest and are, 
historically and conceptually, among the simplest methods one can use. Because of the way the framework is 
organised, it can be used with all **Relauncher** assessors and can call any algorithm from **NLopt** or 
**Vizir**.

Apart from what is presented in [](#calibration_minimisation_optimisation_properties), the `TMinimisation` class does not provide any additional 
options or methods beyond those available in the default `TCalibration` object (see [](#calibration_classes_functions_observations)). 

The usage of the `TMinimisation` class can be summarised in a few key steps:

1. Prepare the data and the model:
   - Specify the experimental dataserver, the parameters to calibrate, and the model;
   - Construct the `TMinimisation` object with the appropriate distance function (see [](#calibration_minimisation_constructing)).

2. Set the algorithm properties:
   - Define optimisation algorithm and prepare its properties (see [](#calibration_minimisation_optimisation_properties)).

3. Perform the estimate and analyse the results:
   - Run the estimate process;
   - Extract the results and visualise them with the standard plotting tools (see [](#calibration_minimisation_results)).

```{toctree}
minimisation/constructing
minimisation/optimisation_properties
minimisation/results
```

Two examples are also provided in the use-case section (see [](#use_cases_macro_calibration_minimisation) and [](#use_cases_macro_calibration_minimisation_vizir)).