[RESOLVED] help me understand how to use this module plz

[lplover2k]

i want to find the eigenvectors and eigenvalues for a matrix... can someone help me use this module from

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'This code is generated by the AlgoPascal translator
'
'This code is distributed under the ALGLIB license
'    (see [url]http://www.alglib.net/copyrules.php[/url] for details)
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'This routines must be defined by the programmer
' Function TridiagonalEVD(ByRef D() As Double, _
'         ByRef E_() As Double, _
'         ByVal N As Long, _
'         ByVal ZNeeded As Long, _
'         ByRef Z() As Double) As Boolean
' Sub ToTridiagonal(ByRef A() As Double, _
'         ByVal N As Long, _
'         ByVal IsUpper As Boolean, _
'         ByRef Tau() As Double, _
'         ByRef D() As Double, _
'         ByRef E() As Double)
' Sub UnpackQFromTridiagonal(ByRef A() As Double, _
'         ByRef N As Long, _
'         ByRef IsUpper As Boolean, _
'         ByRef Tau() As Double, _
'         ByRef Q() As Double)
 
 
'Routines
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'Finding the eigenvalues and eigenvectors of a symmetric matrix
'
'The algorithm finds eigen pairs of a symmetric matrix by reducing it to
'tridiagonal form and using the QL/QR algorithm.
'
'Input parameters:
'    A       -   symmetric matrix which is given by its upper or lower
'                triangular part.
'                Array whose indexes range within [1..N, 1..N].
'    N       -   size of matrix A.
'    IsUpper -   storage format.
'    ZNeeded -   flag controlling whether the eigenvectors are needed or not.
'                If ZNeeded is equal to:
'                 * 0, the eigenvectors are not returned;
'                 * 1, the eigenvectors are returned.
'
'Output parameters:
'    D       -   eigenvalues in ascending order.
'                Array whose index ranges within [1..N].
'    Z       -   if ZNeeded is equal to:
'                 * 0, Z hasn’t changed;
'                 * 1, Z contains the eigenvectors.
'                Array whose indexes range within [1..N, 1..N].
'                The eigenvectors are stored in the matrix columns.
'
'Result:
'    True, if the algorithm has converged.
'    False, if the algorithm hasn't converged (uncommon case).
'
'  -- ALGLIB --
'     Copyright 2005 by Bochkanov Sergey
'
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Public Function SymmetricEVD(ByRef A_() As Double, _
         ByVal N As Long, _
         ByVal ZNeeded As Long, _
         ByVal IsUpper As Boolean, _
         ByRef D() As Double, _
         ByRef Z() As Double) As Boolean
    Dim Result As Boolean
    Dim A() As Double
    Dim Tau() As Double
    Dim E() As Double
    A = A_
 
    Call ToTridiagonal(A, N, IsUpper, Tau, D, E)
    If ZNeeded = 1# Then
        Call UnpackQFromTridiagonal(A, N, IsUpper, Tau, Z)
    End If
    Result = TridiagonalEVD(D, E, N, ZNeeded, Z)
 
    SymmetricEVD = Result
End Function

i got this module from http://www.alglib.net/eigen/symmetric/symmevd.php .. i have add the ap lib module and this module...

i used that code to test the function SymmetricEVD

Private Sub Command1_Click()
Dim mat(0 To 1, 0 To 1), Result(0 To 1, 0 To 1), eigenvect(0 To 1, 0 To 1) As Double
 
mat(0, 0) = 1
mat(0, 1) = 2
mat(1, 0) = 3
mat(1, 1) = 4
 
Call SymmetricEVD(mat, 2, 1, True, Result, eigenvect)
End Sub

but i get "type mismatch"

[Hack]

i get "type mismatch"

On what line?

[timeshifter]

And don't bother with the "Call" part. The function name will be returned as a Boolean variable, so for your return, put something like this:

MsgBox SymmetricEVD(mat, 2, 1, True, Result, eigenvect)

[bushmobile]

but i get "type mismatch"

well mat and result aren't declared as double, they're declared as variants, it should be:

Dim mat(0 To 1, 0 To 1) As Double, Result(0 To 1, 0 To 1) As Double, eigenvect(0 To 1, 0 To 1) As Double

[lplover2k]

BushMobile: thank u!!!

[Grimfort]

http://www.vbforums.com/showthread.p...44#post2766544 bah.