11.2. Description of options of an algorithm by “AlgorithmParameters”

Each algorithm can be controlled using some specific options or parameters. They are given through the “Parameters” optional command included in the mandatory command “AlgorithmParameters”.

There are 3 practical methods for the user of the EFICAS graphical user interface of ADAO (GUI) to provide these options. The method is determined as follows in the ADAO EFICAS graphical user interface:

  1. firstly using the “Parameters” keyword in the “AlgorithmParameters” command, which allows to choose between “Defaults” (use of explicit pre-filled keywords by default parameters values) and “Dict” (use of a dictionary to fill the necessary keywords),
  2. then secondly or thirdly, only in the “Dict” case of “Parameters”, by the included keyword “FROM” which allows to choose between a string entry and a Python script file entry.

These two last options can be also used in the ADAO textual interface (TUI), through the keywords “Parameters” and “Script” of the corresponding command “AlgorithmParameters” (see the [DocR] Textual User Interface for ADAO (TUI/API) part for detailed description).

If an option or a parameter is specified by the user for an algorithm that does not support it, the option is simply ignored (left unused) and don’t stop the treatment. The meaning of the acronyms or particular names can be found in the index or the Glossary.

First method : using explicit pre-filled keywords

To give the parameters values by explicit pre-filled keywords, directly in the graphical interface, the user selects the type “Defaults” in the keyword “Parameters”, then the keywords in the given “Parameters[Algo]” list which appears, linked with the chosen algorithm, as shown in the following figure:

_images/adao_algopar_defaults.png

Using explicit pre-filled keywords for algorithmic parameters

Each parameter is optional, and it is presented with its default value when it is selected by the user. One can then modify its value, or fill it in list cases for example.

It is the recommended way to modify only some algorithmic parameters in a safe way. This method allows only to define authorized parameters for a given algorithm, and the defined values are not kept if the user changes the algorithm.

This method is naturally not usable in TUI interface.

Second method : using a string in the graphical interface

To give the parameters values as a string, directly in the graphical interface, the user selects the type “Dict” in the keyword “Parameters”, then the type “String” in the keyword “FROM” of the “Dict” command which appears, as shown in the following figure:

_images/adao_algopar_string.png

Using a string for algorithmic parameters

In the entry, one must enclose a standard dictionary definition between simple quotes, as for example:

'{"MaximumNumberOfIterations":25,"SetSeed":1000}'

It is the recommended way to define algorithmic parameters. This method allows in particular to keep options or parameters for other algorithms than the currently used one. It is then easier to change of algorithm or to keep default values different of the standard defaults.

In the textual interface TUI, the dictionary has only to be given as argument of the “Parameters” keyword.

Third method : using an external Python script file

To give the parameters values as an external Python script file, the user selects in the graphical interface the type “Dict” in the keyword “Parameters”, then the type “Script” in the keyword “FROM” of the “Dict” command which appears, as shown in the following figure:

_images/adao_algopar_script.png

Using an external file for algorithmic parameters

This external Python script file has then to define a variable with the required name “AlgorithmParameters”, as in the following example:

AlgorithmParameters = {
    "MaximumNumberOfIterations" : 25,
    "StoreSupplementaryCalculations" : ["APosterioriCovariance","OMA"],
    }

The file can also contain other Python commands. This method also allows, as the previous one, to keep options or parameters for other algorithms than the currently used one.

In the textual interface TUI, the file name has only to be given as argument of the “Script” keyword.