SourcePathReceiver Object Attributes

The SPR objects in ForceFinder contain several attributes that are useful to review in the ISE process. The definitions for the different attributes are included in the glossary below.

Warning

In general, the class attributes should be treated as read-only variables once the SPR object is created, unless they are being modified through a class method (e.g., how the response_transformation attribute is modified by the apply_response_weighting method). Technically, some attributes can be overwritten or modified, but this is considered bad practice. Further, some operations, which may seem logical for a SDynPy user will not work in ForceFinder. For example, the spr_object.frfs.ordinate = data command will not write or modify any data into the SPR object.

abscissa

The frequency vector for the frequency domain data in the SPR object.

abscissa_spacing

The frequency resolution for the frequency domain data in the SPR object.

buzz_cpsd (PowerSourcePathReceiver only)

The so-called buzz CPSD that is used to update the training_response when the buzz method is applied.

force

The source, as a SDynPy object, for the SPR object.

frfs

All the FRFs, as a SDynPy TransferFunctionArray, for the SPR object.

predicted_response

The response that is computed by applying the force attribute to the frfs attribute. It is returned as a SDynPy object.

reconstructed_target_response

The response that is computed by applying the force attribute to the target_frfs attribute. It is returned as a SDynPy object.

reconstructed_training_response

The response that is computed by applying the force attribute to the training_frfs attribute. It is returned as a SDynPy object.

reconstructed_validation_response

The response that is computed by applying the force attribute to the validation_frfs attribute. It is returned as a SDynPy object.

reference_coordinate

A SDynPy CoordinateArray the describes the source DOFs in the SPR object.

reference_transformation

The transformation that is applied to the force attribute and reference DOFs in the training_frfs. It is returned as a SDynPy Matrix object.

response_coordinate

A SDynPy CoordinateArray the describes the response DOFs in the frfs attribute.

response_transformation

The transformation that is applied to the training_response attribute and response DOFs in the training_frfs. It is returned as a SDynPy Matrix object.

target_frfs

The frfs that were assigned at SPR object initialization by indexing frfs attribute with the target_response_coordinate attribute. Note that the data for this attribute is stored as a separate private attribute (from the other FRF attributes) in the object. It is returned as a SDynPy TransferFunctionArray.

target_response

The responses in the SPR object, which have the target_response_coordinate as the response DOFs. Note that these responses can be assigned several ways and are stored as a separate private attribute (from the other response attributes) in the object. It is returned as a SDynPy object.

target_response_coordinate

The response DOFs in the target_frfs and target_response attributes. This DOF set is the concatenation of the training_response_coordinate and validation_response_coordinate attributes. It is returned as a SDynPy CoordinateArray.

time_abscissa (TransientSourcePathReceiver only)

The time vector for the time domain data in the SPR object.

time_abscissa_spacing (TransientSourcePathReceiver only)

The sampling time for the time domain data in the SPR object.

training_frfs

The FRFs in the SPR object that are used for the ISE, which have the training_response_coordinate as the response DOFs. These FRFs can be supplied separately from the other FRFs in the SPR object and the data for this attribute is stored as a separate private attribute (from the other FRF attributes) in the object. It is returned as a SDynPy TransferFunctionArray.

training_response

The responses in the SPR object that are used for the ISE, which have the training_response_coordinate as the response DOFs. These responses can be supplied separately from the other responses in the SPR object and the data for this attribute is stored as a separate private attribute (from the other response attributes) in the object. It is returned as a SDynPy object.

training_response_coordinate

The response DOFs for the FRFs and responses in the SPR object that are used for the ISE. It is returned as a SDynPy CoordinateArray.

transformed_force

The source for the SPR object with the reference_transformation applied. It is returned as a SDynPy object.

transformed_reconstructed_response

The reconstructed_training_response attribute with the response_transformation applied. It is returned as a SDynPy object.

transformed_reference_coordinate

The source DOFs that the force attribute is transformed into after the reference_transformation is applied. It is returned as a SDynPy CoordinateArray.

transformed_response_coordinate

The response DOFs that the training_response attribute is transformed into after the response_transformation is applied. It is returned as a SDynPy CoordinateArray.

transformed_training_frfs

The training_frf attribute with the response_transformation and reference_transformation applied. It is returned as SDynPy TransferFunctionArray.

transformed_training_response

The training_response attribute with the response_transformation applied. It is returned as a SDynPy object.

validation_frfs

The frfs that were assigned at SPR object initialization by indexing frfs attribute indexed with the validation_response_coordinate attribute. Note that the data for this attribute is stored as a separate private attribute (from the other FRF attributes) in the object. It is returned as a SDynPy TransferFunctionArray.

validation_response

The target_response attribute that has been indexed with the validation_response_coordinate. It is returned as a SDynPy object.

validation_response_coordinate

The response DOFs that do not exist in the intersection between target_response_coordinate and training_response_coordinate.

Required Attributes for Object Initialization

In most cases, SPR objects will need to be initialized with data for at least the FRFs and responses through the frfs attribute and either the target_response or training_response attributes. Additional data can be supplied at SPR at initialization, including the force, training_response_coordinate, training_frfs, response_transformation, and reference_transformation attributes. A buzz_cpsd can also be supplied, but only for the PowerSourcePathReceiver.

Note

Many of the SPR object attributes will be set to default values or duplicated from other attributes if specific data is not supplied at object initialization. For example, the frfs and training_frfs attributes will be the same if sufficient data is not supplied to determine a difference between the two. Similarly the reference_transformation and response_transformation attributes will default to identity if data is not supplied for them at initialization.