Writing mat file from fortran

I am trying to save an array generated in Fortran to mat file so that i can read it in matlab. I am using gfortran to compile the code.

Basically I have in fortran code (it is dirty based on matdemo1.F) is pasted below. The error during compile is:

/usr/bin/ld: /tmp/ccZi95JS.o: in function `MAIN__':
matdemo.F90:(.text+0x89): undefined reference to `matopen800_'
/usr/bin/ld: matdemo.F90:(.text+0x19c): undefined reference to `mxgetdoubles800_'
/usr/bin/ld: matdemo.F90:(.text+0x1c3): undefined reference to `mxcopyreal8toptr800_'
/usr/bin/ld: matdemo.F90:(.text+0x1e5): undefined reference to `matputvariableasglobal800_'
/usr/bin/ld: matdemo.F90:(.text+0x276): undefined reference to `matclose800_'
/usr/bin/ld: matdemo.F90:(.text+0x307): undefined reference to `mxdestroyarray800_'
collect2: error: ld returned 1 exit status

Which i guess is cause by some missing links but I cannot find anywhere any working example. Only mentions about some 'MEX' code which however seems to have to be compiled by Matlab. I want to compile my code in gfortran, not matlab, I just need to save mat files. Is there some useful existing code that can be reused?

program matdemo1

!     Declarations
implicit none

mwPointer matOpen, mxCreateNumericArray 

#if MX_HAS_INTERLEAVED_COMPLEX
    mwPointer mxGetDoubles
    #else
    mwPointer mxGetPr
    #endif
    
    mwPointer mp, pa
    integer status, matClose, mxIsFromGlobalWS
    integer matPutVariable, matPutVariableAsGlobal
    integer*4 mxIsNumeric, mxIsChar
    integer*4 classid
    integer*4 mxClassIDFromClassName
    integer n, i
    real*8 :: dat(24) = (/(i, i=1, 24, 1)/)
    real*8, dimension(2,3,4) :: dats
    mwSize M
    parameter(M = 3)
    !       mwSize, dimension(M) :: dimens
    integer, dimension(M) :: idimens = (/ 2, 3, 4 /)
    !  	INTEGER, DIMENSION(5) :: ARR = (/ 1, 3, 6, 7, 9 /)
    
    !
    !     Open MAT-file for writing
    !
    write(6,*) 'Creating MAT-file matdemo.mat ...'
    mp = matOpen('matdemo.mat', 'w')
    if (mp .eq. 0) then
        write(6,*) 'Can''t open ''matdemo.mat'' for writing.'
        write(6,*) '(Do you have write permission in this directory?)'
        stop
    end if
    	!
    	!     Create variables
    	!
        !       dimens(1) = idimens(1)
        !       dimens(2) = idimens(2)
        !       dimens(3) = idimens(3)
        !       n = dimens(1)*dimens(2)*dimens(3)
        !       dats = reshape(dat,idimens)
        !       classid = mxClassIDFromClassName('double')
        !       pa = mxCreateNumericArray(M,dimens,classid,0)
        pause
        
        #if MX_HAS_INTERLEAVED_COMPLEX
            call mxCopyReal8ToPtr(dats, mxGetDoubles(pa), n)
            #else
            call mxCopyReal8ToPtr(dat, mxGetPr(pa), n)
            #endif
        	!
            status = matPutVariableAsGlobal(mp, 'NumericGlobal', pa)
            if (status .ne. 0) then
                write(6,*) 'matPutVariableAsGlobal ''Numeric Global'' failed'
                stop
            end if
                
                status = matClose(mp)
                if (status .ne. 0) then
                    write(6,*) 'Error closing MAT-file'
                    stop
                end if
                	!
                	!     clean up memory
                    call mxDestroyArray(pa)
                	!
                    write(6,*) 'Done creating MAT-file'
                    stop
                end

[James Tursa]

You are probably going to need to #include "fintrf.h" in your code so that the MATLAB symbols are defined. Also, how are you compiling your code? I.e., what are the commands you are using to compile your code to ensure you are linking with the MATLAB libraries?