CLsqFit:GetNumCoefs

CLsqFit:GetNumCoefs

The GetNumCoefs method returns the number of coefficients used in the fit or the number of coefficients used in the n-th dimension of the n-dimensional polynomial fit.

Syntax

CLsqFit:GetNumCoefs( nDim* )

nDim is an optional argument that specifies the dimension when the n-dimensional polynomial basis function is used. If, however, the polynomial is used with 1 dimension, this argument is not needed..

Remarks

This method returns a value between 1 and the total number of coefficients set by the SetNumCoefs method. Depending on the basis function being used, this method returns the values described below:

n-dimensional polynomial: This method returns either the total number of coefficients being fit or the number of coefficients used in the n-th dimension. For example, if the script called SetNumCoefs( 5, 3 ), then GetNumCoefs() returns 15, GetNumCoefs( 1 ) returns 5, and GetNumCoefs( 2 ) returns 3. For dimensions higher than that specified for the polynomial, GetNumCoefs( n ) returns 1.
Hyperplane: This method returns the number of coefficients fit by the hyperplane, which includes 1 coefficient for a constant term. For example, if the hyperplane fits 5 variables, this method returns 6
User-specified basis function: This method returns the number of coefficients used by the basis function. For example, if the basis function fits 8 coefficients to 3 dimensions, this method returns 8.

Examples

The first example, below, defaults to fitting the built-in n-dimensional polynomial. This script specifies 3 coefficients for fitting a 2nd order polynomial to 1 variable. Since only 1 argument is specified, the polynomial fits 1 independent variable.

L = CLsqFit:new()	-- create a CLsqFit object
L:SetNumCoefs( {3, 5} )	-- set 3x5 coefficients for the n-dimensional polynomial
n = L:GetNumCoefs()	-- return the number of coefficients
Printf( "n = %d\n", n )	-- result: n= 15
n = L:GetNumCoefs(1)	-- return the number of coefficients in dimension 1
Printf( "n[%d] = %d\n", 1, n )	-- result: n[1] = 3
n = L:GetNumCoefs(2)	-- return the number of coefficients in dimension 2
Printf( "n[%d] = %d\n", 2, n )	-- result: n[2] = 5

The next example used a basis function defined in the script (not the built-in n-Dimensional Polynomial). For this case, GetNumCoefs returns the number of coefficients set by the SetNumCoefs method:

L = CLsqFit:new()	-- create a CLsqFit object
L:SetBasisFunc( "F" )	-- specify a basis function named "F"
L:SetNumCoefs( 9, 5 )	-- set 9 coefficients and 5 independent variables
n = L:GetNumCoefs()	-- return the number of coefficients
Printf( "nCoefs = %d\n", n )	-- result: nCoefs = 9