External Interfaces/API

Reading a MAT-File in Fortran

This sample program illustrates how to use the library routines to read in the MAT-file created by matdemo1.f and describe its contents.

• C     matdemo2.f
  C
  C     This is a simple program that illustrates how to call the
  C     MATLAB MAT-file functions from a Fortran program.  This
  C     demonstration focuses on reading MAT-files. It reads in
  C     the MAT-file created by matdemo1.f and describes its
  C     contents.
  C
  C     Copyright (c) 1984-2000 The MathWorks, Inc.
  C     $Revision: 1.9 $
  
        program matdemo2
  C--------------------------------------------------------------
  -
  C     (pointer) Replace integer by integer*8 on the DEC Alpha
  C     64-bit platform
  
        integer matOpen, matGetDir, matGetNextVariable
        integer matGetNextVariableInfo
        integer mp, dir, adir(100), pa
  C--------------------------------------------------------------
  -
  
  C     Other variable declarations here.
        integer   mxGetM, mxGetN, matClose
        integer   ndir, i, stat
        character*32 names(100), name
  
  C     Open file and read directory.
        mp = matOpen('matdemo.mat', 'r')
        if (mp .eq. 0) then
           write(6,*) 'Can''t open ''matdemo.mat''.'
           stop
        end if
  
        dir = matgetdir(mp, ndir)
        if (dir .eq. 0) then
           write(6,*) 'Can''t read directory.'
           stop
        endif
  
  C     Copy pointer into an array of pointers.
        call mxCopyPtrToPtrArray(dir, adir, ndir)
  
  C     Copy pointer to character string.
        do 20 i=1,ndir
           call mxCopyPtrToCharacter(adir(i), names(i), 32)
     20 continue
  
        write(6,*) 'Directory of Mat-file:'
        do 30 i=1,ndir
           write(6,*) names(i)
     30 continue
  
        stat = matClose(mp)
        if (stat .ne. 0) then
           write(6,*) 'Error closing ''matdemo.mat''.'
           stop
        end if
  
  C     Reopen file and read full arrays.
        mp = matOpen('matdemo.mat', 'r')
        if (mp .eq. 0) then
           write(6,*) 'Can''t open ''matdemo.mat''.'
           stop
        end if
  
  C     Get Information on first array in mat file.
        write(6,*) 'Getting Header info from first array.'
        pa = matGetVariableInfo(mp, names(1))
        write(6,*) 'Retrieved ', names(1)
        write(6,*) '  With size ', mxGetM(pa), '-by-', mxGetN(pa)
        call mxDestroyArray(pa)
        
        write(6,*) 'Getting Header info from next array.'
        pa = matGetNextVariableInfo(mp, name)
        write(6,*) 'Retrieved ', name
        write(6,*) '  With size ', mxGetM(pa), '-by-', mxGetN(pa)
        call mxDestroyArray(pa)
  
  C     Read directory.
        write(6,*) 'Getting rest of array contents:'
        pa = matGetNextVariable(mp, name)
  
  C     Copy name to character string.
        do while (pa .ne. 0)
           i=mxGetM(pa)
           write(*, *) i 
           write(6,*) 'Retrieved ', name
           write(6,*) '  With size ', mxGetM(pa), '-by-', mxGetN(pa)
           call mxDestroyArray(pa)
           pa = matGetNextVariable(mp, name)
        end do
  
        stat = matClose(mp)
        if (stat .ne. 0) then
           write(6,*) 'Error closing ''matdemo.mat''.'
           stop
        end if
        stop
        end
  

After compiling and linking this program, you can view its results.

•  matdemo2
   Directory of Mat-file:
   String                          
   Numeric                         
   Getting full array contents:
     1
   Retrieved String                          
     With size   1-by-  33
     3
   Retrieved Numeric                         
     With size   3-by-  3
  

Creating a MAT-File in Fortran

Compiling and Linking MAT-File Programs