Trouble using a derived data type in a subroutine - f90

[lordhaworth]

The title says it all really. It could be something really simple im doing wrong, the snapshot of code that doesnt work is below



TYPE GRID
REAL :: Temperature, Density
END TYPE

INTEGER :: XMax = 100, YMax = 100
TYPE(GRID),DIMENSION(XMax, YMax) :: DataGrid

INTERFACE
SUBROUTINE Setup_Density_Distribution(InfoGrid)
TYPE(GRID), DIMENSION(XMax, YMax), INTENT(INOUT) :: InfoGrid
END SUBROUTINE

SUBROUTINE Setup_Temperature_Distribution(InfoGrid)
TYPE(GRID), DIMENSION(XMax, YMax), INTENT(INOUT) :: InfoGrid
END SUBROUTINE
END INTERFACE



So im basically defining a data type and wanting to pass an array of this data type to an external subroutine. However at the moment I get the following error message:

"Error: Derived type 'grid' at (1) is being used before it is defined"

I've tried re ordering the above code to no avail, I dont get it because I can get derived types to work, and I can get subroutines using an interface to work - just not together!

Any help or suggestions would be greatly appreciated!


Thanks very much all

Tom :)

[WW]

Wrap the type definition in a module, and use it before the declaration of the variables. E.g.


module grid_type
TYPE GRID
REAL :: Temperature, Density
END TYPE
end module grid_type

use grid_type
INTEGER :: XMax = 100, YMax = 100
TYPE(GRID),DIMENSION(XMax, YMax) :: DataGrid

INTERFACE
SUBROUTINE Setup_Density_Distribution(InfoGrid)
use grid_type
TYPE(GRID), DIMENSION(XMax, YMax), INTENT(INOUT) :: InfoGrid
END SUBROUTINE

SUBROUTINE Setup_Temperature_Distribution(InfoGrid)
use grid_type
TYPE(GRID), DIMENSION(XMax, YMax), INTENT(INOUT) :: InfoGrid
END SUBROUTINE
END INTERFACE

[lordhaworth]

thats brilliant cheers, I never would have figured that out!

Thanks again