Fortran 90 with Excel – gfortran example

Recently i created a program that involved Fortran and excel.  The main solving was handled by the Fortran and excel provided the GUI.

I know many people search for this so here’s the small example that i worked on before going to the main program.

I used gfortran as Fortran compiler and Excel 2003 for the GUI.

Fortran program accepts and array and does some calculation and returns the values back to excel.

The excel VBA code, call the Fortran dll and then the results form the dll call are posted in excel cells.

Here’s the Fortran program

        Subroutine FortranDLL( Array1, upbound )
        Implicit None
! …argument declarations
        Integer :: upbound
        Integer :: Array1(1:upbound)
! Local variables
        Integer :: i
        do i=1,upbound
        Array1(i)=288.16-0.0065*Array1(i)
        end do
        End Subroutine FortranDLL

It was compiled with the following options.

gfortran -mrtd -fno-underscoring -shared -o fortrandll.dll fortrandll.f90

And here’s what I did in the excel.

Declare Sub fortrandll Lib "C:\TEMP\fortrandll.dll" (ByRef Array1 As Double, ByRef upbound As Long)

Sub Button1_Click()
    Dim II As Long
    Dim test(10) As Double
    II = 11
    Call fortrandll(test(1), II)
    Range("a1").Value = test(1)
    Range("a2").Value = test(2)
    Range("a3").Value = test(3)
    Range("a4").Value = test(4)
    Range("a5").Value = test(5)
    Range("a6").Value = test(6)
    Range("a7").Value = test(7)
    Range("a8").Value = test(8)
    Range("a9").Value = test(9)
    Range("a10").Value = test(10)
End Sub

Will post more in coming weeks. Maybe a full fledged excel application using a fortran dll.