how to extend array bounds

[jackmwl]

Hi everyone,

There is an allocatable array Ap(100000) required to be extended to A(1000000).
The code is used to do this as follows,

ALLOCATE(A(1000000))
A(:100000)=Ap
DEALLOCATE(Ap)

But I am not sure this is an efficient way. So how to extend the allocatable arraysize from 100,000 to 1000,000 more efficiently?

Any help would be highly appreciated!

Best regards

Jack

[Jugoslav_Dujic]

Check out MOVE_ALLOC in your manual. There is also a reallocation sample.

[jackmwl]

Hi Jugoslav,

Thanks for your reply!
I am sorry that I didn'tdescribe thequestion clearly.

A(:) is an allocatable array of workspace, but it's uncertain about its size.
Before evaluating the size of A, Ap(:) is used as an temporary allocatable array to store some information instead of A , of which the size is assumed to be 100,000, as shown in the following code.

After evaluating the size of A, A needs to be allocated and store the information as workspace; Ap is not used anymore.

Mycode is used to do this with the size of A 1000,000 as follows,
! Ap is temporary workspace, A does not exist
! evaluate the size of A, then do

ALLOCATE(A(1000000))

A(:100000)=Ap

DEALLOCATE(Ap)
! A is workspace now, Ap is not used

This code works, but I thought that A(:100000)=Ap in this code may be not efficient. So I am trying to find a more efficient way in which maybe Ap or copying values of Ap to A not be needed, and the bounds of A(:) could just be extended from 100,000 to 1000,000 efficiently.

MOVE_ALLOC doesmore than what i need, as follows

! Ap is temporary workspace, A does not exist

! evaluate the size of A, then do

ALLOCATE(A(1000000))

A(:100000)=Ap
MOVE_ALLOC(A,Ap) ! this is not necessary
! Ap is still workspace here, A is not used



Best regards

Jack