14.15. List of commands and keywords for an ADAO checking case¶

We summarize here all the commands and keywords available to describe a checking case, by avoiding the particularities of each algorithm. It is therefore a common inventory of commands.

A special term allow to choose explicitly a checking. In the graphical user interface, this choice is done by the command “CHECKING_STUDY”.

All the possible terms, nested or not, are listed by alphabetical order. They are not required for all the algorithms. The commands or keywords available are the following

AlgorithmParameters: Dictionary. This variable indicates the data assimilation or optimization algorithm chosen by the keyword “Algorithm”, and its potential optional parameters. The potential choices by this keyword “Algorithm” are available through the graphical interface or in the reference documentation containing a specific sub-section for each of them. There are for example the “3DVAR”, the “Blue”, etc. Optionally, the command also allows to add parameters to control the chosen algorithm. Their values are defined either explicitly or in a “Dict” type object. See the Description of options of an algorithm by “AlgorithmParameters” for the detailed use of this command part.

BackgroundError: Matrix. This indicates the background error covariance matrix, previously noted as $\mathbf{B}$ . Its value is defined as a “Matrix” type object, a “ScalarSparseMatrix” type object, or a “DiagonalSparseMatrix” type object, as described in detail in the section Requirements to describe covariance matrices. Its availability in output is conditioned by the boolean “Stored” associated with input.

CheckingPoint: Vector. The variable indicates the vector used as the state around which to perform the required check, noted $\mathbf{x}$ and similar to the background $\mathbf{x}^b$ . It is defined as a “Vector” or “VectorSerie” type object. Its availability in output is conditioned by the boolean “Stored” associated with input.

CHECKING_STUDY: Required command. This is the general command describing the checking case. It hierarchically contains all the other commands.

Debug

Boolean value. This variable define the level of trace and intermediary debug information. The choices are limited between 0 (for False) and 1 (for True).

Example : {"Debug":False}

ExecuteInContainer: String. This variable allows to choose the execution mode in YACS in a specific container. In its absence or if its value is “No”, no separate container is used for execution and it runs in the main YACS process. If its value is “Mono”, a specific YACS container is created and it is used to host the execution of all nodes in the same process. If its value is “Multi”, a specific YACS container is created and it is used to host the execution of each node in a specific process. The default value is “No”, and the possible choices are “No”, “Mono” and “Multi”.

Warning

In its present version, this command is experimental, and therefore remains subject to changes in future versions.

Observation: List of vectors. The variable indicates the observation vector used for data assimilation or optimization, and usually noted $\mathbf{y}^o$ . Its value is defined as an object of type “Vector” if it is a single observation (temporal or not) or “VectorSeries” if it is a succession of observations. Its availability in output is conditioned by the boolean “Stored” associated in input.

ObservationError: Matrix. The variable indicates the observation error covariance matrix, usually noted as $\mathbf{R}$ . It is defined as a “Matrix” type object, a “ScalarSparseMatrix” type object, or a “DiagonalSparseMatrix” type object, as described in detail in the section Requirements to describe covariance matrices. Its availability in output is conditioned by the boolean “Stored” associated with input.

ObservationOperator: Operator. The variable indicates the observation operator, usually noted as $H$ , which transforms the input parameters $\mathbf{x}$ to results $\mathbf{y}$ to be compared to observations $\mathbf{y}^o$ . Its value is defined as a “Function” type object or a “Matrix” type one. In the case of “Function” type, different functional forms can be used, as described in the section Requirements for functions describing an operator. If there is some control $U$ included in the observation, the operator has to be applied to a pair $(X,U)$ .

Observers: List of functions linked to variables. This command allows to set internal observers, that are functions linked with a particular variable, which will be executed each time this variable is modified. It is a convenient way to monitor variables of interest during the data assimilation or optimization process, by printing or plotting it, etc. Common templates are provided to help the user to start or to quickly make his case.

StudyName: String. This variable is an open string to identify or describe the ADAO study by a name or a sentence.

StudyRepertory: String. If available, the directory specified by this string is used as base name for calculation, and also used to find all the script files given by name without path, that can define some other commands by scripts.

UserDataInit: Script name. This variable allows to initialize some parameters or data automatically before algorithm input processing. It indicates a script file name to be executed before entering in initialization phase of chosen variables.