subroutine RPN_COMM_compress(array,minx,maxx,miny,maxy,nil,njl,nk)
subroutine RPN_COMM_compress8(array,minx,maxx,miny,maxy,nil,njl,nk)
subroutine RPN_COMM_expand(array8,minx,maxx,miny,maxy,nil,njl,nk)
subroutine RPN_COMM_expand8(array8,minx,maxx,miny,maxy,nil,njl,nk)

ARGUMENTS

• array : input array, size (minx:maxx,miny:maxy,nk), real or integer
• array8 : input array, size (minx:maxx,miny:maxy,nk), double precision (integer or real)
• minx,maxx,miny,maxy: maximum size of array
  
• ni,nj,nk: number of points
  

OUT

array, with the compressed (or expanded) data

DESCRIPTION

Compress an array by removing the halo. Typically, the input will have the following shape: (case k=1):

+---------+      
|         |      
| +-----+ |      
| |ni*nj| |    ->       (maxx-minx+1)*(maxy*miny+1) 
| O-----+ |        +---------+----------+-------+-------+
|         |        |ni*nj k=1| ni*nj k=2|...k=nk|       |
+---------+        +---------+----------+-------+-------+

"O" is the origin, the outmost part is of size minx:maxx, miny:maxy and inmost part is ni,nj. The compression process rewrite the inmost part in the outmost part in a way that all ni*nj*nk points are consecutive in the (maxx-minx+1)*(maxy*miny+1) array. Then, we can save (maxx-minx+1)*(maxy*miny+1)-ni*nj*nk at the end of the array. Calling compress8 will do the same trick for double precision arrays.

If we use "expand", we proceed the opposite way, placing the ni*nj*nk first points in an array of size minx:maxx, miny:maxy, beginning at point (1,1,1). Calling expand8 will do the same trick for double precision arrays.

SEE ALSO