databank.eval (+databank)

Evaluate an expression within a databank context

Syntax

[output, output, ...] = databank.eval(inputDb, expression, expression, ...)
outputs = databank.eval(inputDb, expressions)
outputDb = databank.eval(inputDb, expressionsDb)

Input arguments

inputDb [ struct | Dictionary ]

Input databank whose fields constitute a workspace in which the expressions will be evaluated.%

expression [ char | string ]

Text string with an expression that will be evaluated in the workspace consisting of the inputDb fields.

expressions [ cellstr | string ]

Cell array of char vectors or string array (more than one element) with expressions that will be evaluated in the workspace consisting of the inputDb fields.

expressionsDb [ struct | Dictionary ]

Databank whose fields contain the expressions that are to be evaluated.

Output arguments

output [ * ]

Result of the expression evaluated in the inputDb workspace.

outputs [ cell ]

Results of the expressions evaluated in the inputDb workspace.

outputDb [ struct | Dictionary ]

Output databank with the results of the expressions evaluated in the inputDb workspace.

Description

Any names, including dot-separated composite names, not immediately followed by an opening parenthesis (round bracket), are treated as inputDb fields. Dot=separated composite names are therefore considered to be fields of databanks nested withing the inputDb.

Any names, including dot-separated composite names, immediately followed by an opening parenthesis (round bracket), are considered calls to functions, and not treated as inputDb fields.

To include round-bracket references to inputDb fields (such as references to elements of arrays), include an extra space between the name and the opening parenthesis.

Example

d = struct( );
d.aaa = [1, 2, 3];
databank.eval('10*aaa(2)')

will fail with a Matlab error unless there is function named aaa existing in the current workspace. This is because aaa(2) is considered to be a call to a function named aaa, and not a reference to the field existing in the databank d.

To refer the second element of the field aaa, include an extra space between aaa and (

 databank.eval('10*aaa (2)')