Adams Basic Package > Adams View > View Command Language > optimize > optimize fit_response_surface

optimize fit_response_surface

The FIT_RESPONSE_SURFACE command fits a surface of arbitrary polynomial degree to a given set of result set components. Usually, the dependent data is the response component produced by a DOE, and the independent data values are the design variable values used to compute the response.

The polynomial data can be stored in a new result set, and also written to a file (say, for use by a spreadsheet program).

Format:

optimize fit_response_surface
result_set_name=	result_set name
dependent_variable=	existing component
independent_variables=	existing component
polynomial_degrees=	integer
file_name=	string

Description:

Parameter	Value Type	Description
result_set_name	Result Set Name	This parameter allows you to identify a result set name
dependent_variable	Existing Component	The DEPENDENT_VARIABLE specifies the result set which is the left-hand side of the fit equation. DEPENDENT_VARIABLE = F(INDEPENDENT_VARIABLES) Usually, this result set is the response values of an experiment.
independent_variables	Existing Component	The INDEPENDENT_VARIABLES specify the result sets which are the right-hand side of the fit equation. DEPENDENT_VARIABLE = F(INDEPENDENT_VARIABLES) Usually, these result sets were the experimental values of the design variables in an experiment.
polynomial_degrees	Integer	The POLYNOMIAL_DEGREES parameter specifies the highest degree for each of the indpendent variables.
file_name	String	Specifies the name of the file that is to be read, written, or executed.

Extended Definition:

1. A result set is a storage place for any kind of numeric tabular data. A result set can contain "n" components. A component is most usually setup to contain vector components of values like displacement, velocity, acceleration, force, etc. However, in this case a result set is completely general and can store any numeric value in a component with only few exceptions. These exceptions are those cases when the user asks the system to mix incompatible value types like complex in the same component as real values.

This is a required parameter and the result set name given must be within a particular analysis. A result set name may be arbitrarily long and a combination of letters of the alphabet and numbers may be used. The leading character must be a letter.

Result Sets are associated with an analysis run and can be identified as such. A result set associated with request 101 from an analysis named "test" is referred to as .test.req101.

Several predefined result set types are created when Adams request and result files are read into Adams View. For example, assume you have read a request file called "SHIFT.REQ", and this request file contains the result information for the Adams statement REQUEST/1. The result set will be named REQ1, and may also be referred to relative to the analysis name .shift.req1. If you wish to refer to a component in the same result set, the full name for the X component would be .SHIFT.REQ1.X.

The following table illustrates the default names assigned to result sets and result set components read from request (.REQ) and results (.RES) files.

Result set type	Result set name	Component Name	File that result is from
Part	AR xxx	x y z e le2e3 e4mag vx vy vz wx wy wz acc	Result file
diff	diffxxx	q dq	results file
joint	JOIxxx	fx fy fz tx ty tzfmag tmag	results file
jprim	JPRxxx..	fx fy fz tx ty tz fmag tmag	results file
motion	MOTxxx...	fx fy fz tx ty tz fmag tmag	results file
gear	GEAxxx..	fx fy fz	results file
coupler	COUxxx...	fx1 fy1 fz1 tx1 ty1 tz1 fmag1 tmag1	results file
sforce	SFOxxx...	fx fy fz tx ty tz fmag tmag	results file
spring damp	SPRxxx..	fx fy fz tx ty tz fmag tmag	results file
Bushing	BUSxxx...	fx fy fz tx ty tz fmag tmag	results file
Beam	BEAxxx...	fx fy fz tx ty tz fmag tmag	results file
Field	FIExxx...	fx fy fz tx ty tz fmag tmag	results file
User Request	UREQxxx...	x y z r1 r2 r3 mag amag	Request file
Ucon	Not implemented+
request	REQxxx...

2. For example, if you have specified two independent variables, you would enter POLYNOMIAL_DEGREES=1,1 for a linear approximation. For a polynomial fit which is cubic in the first variable and linear in the second, you would enter POLYNOMIAL_DEGREES=3,1.

3. The proper extension for the file_name parameter is the default but can be overridden by simply supplying a different extension.

You do not need to enclose the file name in quotes if it only contains alpha-numeric characters and starts with a letter. If you want to include other characters, such as a '.' for an extension or '/' or '[]' for directory paths, you must enclose the name in quotes.