I’m trying to extract x,y,z coordinate from cgns 2-D mesh file.

I am using FORTRAN90 code and I use the cg_coord_read_f.

I have to call this function many times. So, I want to run the process using subroutine. But it isn’t work.

The first version is following. It open the test.cgns file, and read CoordinateX, print them.

        program extractor_panel
        use cgns
        parameter (izmx=200,iptmx=100000)
        integer(4) :: index_file, index_zone, index_base, ier
        dimension x(iptmx,izmx)

        call cg_open_f('test.cgns',CG_MODE_READ,index_file,ier)

        index_file = 1
        index_zone = 1
        index_base = 1
        irmin=1
        irmax=100
        
        call cg_coord_read_f(index_file, index_zone, index_base, "CoordinateX", RealSingle, irmin, irmax, x, ier)
        print *, x(1,1), x(2,1), x(3,1), x(4,1), x(5,1)
        
        end program

The second version is following.

        program extractor_panel
        ! use cgns
        parameter (izmx=200,iptmx=100000)
        character*9 :: filename

        filename = 'test.cgns'
        
        call test(filename)
        
        end program

        subroutine test(filename)
        parameter (izmx=200,iptmx=100000)
        character*9 :: filename
        integer(4) :: index_file, index_zone, index_base, ier, irmin, irmax
        dimension x(iptmx,izmx)

        call cg_open_f(filename,CG_MODE_READ,index_file,ier)

        index_file=1
        index_zone=1
        index_base=1
        irmin=1
        irmax=10

        call cg_coord_read_f(index_file, index_zone, index_base, "CoordinateX", RealSingle, irmin, irmax, x, ier)
        print *, x(1,1), x(2,1), x(3,1), x(4,1), x(5,1)
        
        end subroutine

The second version simply moves the calling functions into a subroutine. However, the second version has the problem of returning all CoordinateXs to 0.0000.

Because the first version is working well, so there is no problem with cgns and hdf5 libraries.

How can I solve this problem?

It is compiled with 8bit real and integer. There is no problem with cgns and hdf5 libraries. (First version is working well.)