CLsqFit:SetBasisFunc

The SetBasisFunc method selects the basis function to use for the fit. This function selects the two built-in basis functions or a named custom basis function you specify in the script. Before writing a custom basis function, read the Basis Functions topic.

Syntax

CLsqFit:SetBasisFunc( BasisFuncChoice )

BasisFuncChoice is a number 1 or 2 for a built-in basis function.

BasisFuncChoice is a string giving the name of a user-provided function written in the script.

Remarks

This function takes either a number of string value to select the basis function. Mira interprets a number value as a built-in basis function. A string is interpreted as the name of a function in the script:

1	The built-in (default) n-dimensional polynomial basis function.
2	The built-in hyperplane basis function.
strName	The name of a user-provided basis function declared in the script.

Examples

The following script selects the built-in hyperplane basis function.

L = new_lsqfit()	-- create a CLsqFit object
	-- no function declared, so n-dimensional polynomial used
L:SetBasisFunc( 2 )	-- select built-in function 2, the Hyperplane
sName = L:GetBasisFunc()
Printf( "Func= '%s'\n", sName )	-- result: Func= '2'

The next example declares a user-defined basis function in the script. This function fits a line:

function Line( n, c )	-- declare the basis function. n is always passed as 2.
local b = {}	-- declare a local table for the basis vector
b[1] = 1	-- basis vector element [1] is 1
b[2] = c[1]	-- basis vector element [2] is c[1], or the "x" coordinate
return b	-- return the basis vector
end	-- end of the basis function
L = new_lsqfit()	-- create a CLsqFit object
L:SetBasisFunc( "Line" )	-- register the script function "Line"
L:SetNumCoefs(2)	-- set the number of coefs for a 1-dimensional fit.
-- add more points to the fit
L:Fit()	-- fit the data
sName = L:GetBasisFunc()
Printf( "Func= '%s'\n", sName )	-- result: Func= 'Line'

Syntax

Remarks

Examples

Related Topics