Description

Decomposes a wavefront into Zernike polynomials.

Syntax

DecomposeWavefrontToZernikes CoordSys, Ana, Wavefront, X0, Y0, Z0, ASemiAp, BSemiAp, MaxTermNum, Coeffs

Parameters

CoordSys As Long

Node number of the entity in whose coordinate system the Wavefront was calculated.

Ana  As T_ANALYSIS

T_ANALYSIS structure, expressed in CoordSys.  If the LoadAnalysis command is used, the T_ANALYSIS structure is expressed in the Global Coordinate System (specified as -1).  In this case, CoordSys should have a value of -1.

Wavefront() As Double

This array must have the same dimensions as the number of samples in the T_ANALYSIS structure and contains the wavefront data in units of waves.  This array will generally be the result of the Wavefront script command.

X0 As Double

x-coordinate of the origin about which the Zernikes are calculated.  This value is specified in the coordinate system of CoordSys.

Y0 As Double

y-coordinate of origin about which the Zernikes are calculated.  This value is specified in the coordinate system of CoordSys.

Z0 As Double

z-coordinate of origin about which the Zernikes are calculated.  This value is specified in the coordinate system of CoordSys and projected along the normal of the T_ANALYSIS grid to the T_ANALYSIS plane.

ASemiAp As Double

Semi-aperture along the A-axis of the T_ANALYSIS structure over which Zernikes are calculated.

BSemiAp (Double)

Semi-aperture along the B-axis of the T_ANALYSIS structure over which Zernikes are calculated.

MaxTermNum (Long)

Maximum Zernike term number.

Coeffs (Double Array)

Array holding Zernike coefficients.

Example

The example below demonstrates how to use DecomposeWavefrontToZernikes after populating an array of wavefront data.  The resulting coefficients of the decomposition are then reported to the output window.

Sub Main

    Dim ana As Long, det As Long

    ana = FindFullName( "Analysis Surface(s).Wavefront Detector" )

    det = FindFullName( "Geometry.Detector.Surface" )

    'Populate the analysis grid structure

    Dim tAna As T_ANALYSIS

    LoadAnalysis( ana, tAna )

    'Retreive the complex field data

    Dim reals() As Double, imags() As Double

    ScalarField( det, -1, tAna, reals(), imags() )

    'Unwrap the wavefront data

    Dim wf() As Double

    Wavefront( reals(), imags(), wf() )

    'Wavefront analysis and decomposition

    Dim maxCoef As Long, curCoef As Long

    Dim coefs() As Double, xcen As Double, ycen As Double, zcen As Double

    Dim xsemi As Double, ysemi As Double

    Dim isWaves As Boolean

    Dim zstring As String

    isWaves = True

    maxCoef = 15

    xsemi   = 10

    ysemi   = 10

    DecomposeWavefrontToZernikes( -1, tAna, wf(), xcen, ycen, zcen, xsemi, ysemi, maxCoef, coefs() )

    'Report the zernike coefficients

    Print ""

    Print "Zernike decomposition result:"

    Print "" & Chr(9) & "Term" & Chr(9) & "Coef (" & If(isWaves,"waves",GetUnits()) & ")" & Chr(9) & "Form"

    For curCoef = 0 To UBound(coefs)

        Print Chr(9);

        Print curCoef;

        Print coefs(curCoef);

        Print GetZernikeSurfIthTermText( curCoef )

    Next

End Sub

See Also

LoadAnalysis

Wavefront