allocatable array allocated inside subroutine

[jshine]

I'm curious what the best way to return an array of data from inside a subroutine is when the size of the array can't be determined until one is already inside the subroutine.

Due to the nature of the calculation, I can't predict how much storage space I will need before executing the subroutine.

Is it legal to have an allocatable array as a dummy argument of intent "out" and then allocate it inside the subroutine? Or is there a better way to handle this situation?

Thanks in advance!
-Jon

 

[teng22]

I have something similar, perhaps this will help?

In the calling routine have the allocatable array decalared
using dummy arguments

ALLOCATABLE :: TWARRY1,


then I obtain the variable array arguments MAAX and MARD from other calculations


before I allocate, I make sure the temporary array does not exist

IF(ALLOCATED(TWARRY1)) DEALLOCATE(TWARRY1)

now I allocate my temporary array

ALLOCATE (TWARRY1(MAAX,MARD))

and pass it to another sub

CALL WADESC(MAAX,MARD,TWARRY1)

in sub WADESC I have

SUBROUTINE WADESC(NMAAX,NMARD,TWARRY)
INTEGER,INTENT(IN)::NMAAX
INTEGER,INTENT(IN)::NMARD
INTENT(OUT),DIMENSION(NMAAX,NMARD):: TWARRY

within WADESC I am building the detail of TWARRY
at the exit of WADESC, TWARRY is completed

END SUB WADESC

and on returning to the calling routine the temporary array
TWARRY1 is then completed.