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Problem calling an external DLL from VB.Net 2003

Trying to call an external DLL (compiled within Fortran) and keep on getting
the following error in the main call to the external DLL

' Object reference not set to instance of object'

The DLL import definition is located within its own class as follows:
'
'
Imports System.Runtime. InteropServices
'
Public Class LAPACK
'...
<DllImport("C:\ G95\_LAPACK\DGG EV_DLL\dggev.dl l", EntryPoint:="dg gev_",
SetLastError:=T rue, _
CharSet:=CharSe t.Unicode, ExactSpelling:= True, _
CallingConventi on:=CallingConv ention.StdCall) _
Public Shared Sub _
DGGEV(ByVal JOBVL As Char, ByVal JOBVR As Char, ByVal N As Integer, _
ByRef A(,) As Double, ByVal LDA As Integer, ByRef B(,) As Double, _
ByVal LDB As Integer, ByRef ALPHAR() As Double, ByRef ALPHAI() As
Double, _
ByRef BETA() As Double, ByRef VL(,) As Double, ByVal LDVL As Integer, _
ByRef VR(,) As Double, ByVal LDVR As Integer, ByRef WORK() As Double, _
ByVal LWORK As Integer, ByRef INFO As Integer)
End Sub
'
End Class
The main net program calls the procedure as follows

Call LAPACK.DGGEV("N ", "V", N, S, LDA, T, LDA, ALPHR1, ALPHI1, _
BETA1, Q, LDQ, QE, LDQE, WORK, LWORK, IERR)

As soon as the call occurs the error message appears.

Any ideas would be appreciated

Mike C.
Jul 22 '06 #1
0 1789

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