Dakota Reference Manual  Version 6.4
Large-Scale Engineering Optimization and Uncertainty Analysis
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field_responses


Number of field responses functions

Specification

Alias: num_field_responses

Argument(s): INTEGER

Required/Optional Description of Group Dakota Keyword Dakota Keyword Description
Required lengths Lengths of field responses
Optional num_coordinates_per_field Number of independent coordinates for field responses
Optional read_field_coordinates Add context to data: flag to indicate that field coordinates should be read

Description

This keyword describes the number of field response functions. A field function is a set of related response values collected over a range of independent coordinate values which may or may not be specified by the user. For example, voltage over time would be a field function, where voltage is the field_objective and time is the independent coordinate. Similarly, temperature over time and space would be a field response, where the independent coordinates would be both time and spatial coordinates such as (x,y) or (x,y,z), depending on the application. The main difference between scalar responses and field responses is that for field data, we plan to implement methods that take advantage of the correlation or relationship between the field values.

Note that if there is one field_response, and it has length 100 (meaning 100 values), then the user's simulation code must return 100 values. Also, if there are both scalar and field responses, the user should specify the number of scalar responses as scalar_responses. If there are only field responses, it still is necessary to specify both response_functions = NN and field_responses = NN, where NN is the number of field responses.

This type of data set is used by uncertainty quantification methods, in which the effect of parameter uncertainty on response functions is quantified, and can also be used in parameter study and design of experiments methods (although these methods are not restricted to this data set), in which the effect of parameter variations on response functions is evaluated. Currently, field response functions will be translated back to scalar responses. So, a field of length 100 will be treated as 100 separate scalar responses. However, in future versions of Dakota, we plan to implement methods which can exploit the nature of field data.

See Also

These keywords may also be of interest: