PACKER - Multidimensional Data Manipulation

PACKER presents a single interface to the general problem of selecting data or reshaping a multidimensional array. The same routine can handle data that is "really" vector, matrix, 3D, or even higher dimensions. PACKER also "knows about" the fact that some arrays have both a declared or maximal dimension, and a smaller "used" dimension, which affects how the data is stored in memory.

PACKER is most useful for problems like the following: suppose, at run time, I want to consider an array which is indexed by six indices (I,J,K,L,M,N). I want to be able to fix any subset of these indices, (say, I=K=L=N=1) and produce the selected subarray of all data which satisfies these constraints. PACKER can also handle cases where each index is allowed to vary over some specified range.

Files you may copy include:

• packer.f90, the source code;
• packer_prb.f90, the calling program;
• packer_prb.out, the sample output.

The list of routines includes:

• ARRAY_SIZE computes the "size" of an object of given shape.
• INDEX_NEXT generates all indices within given upper limits.
• PACK_GET gets the value of an element of a packed array.
• PACK_INC increments the value of an element of a packed array.
• PACK_SELECT selects a subarray from a packed array.
• PACK_SET sets the value of an element of a packed array.
• TIMESTAMP prints the current YMDHMS date as a time stamp.
• UNPACK_SELECT selects a subarray from an unpacked array.
• UNPACK_TO_PACK converts an unpacked array to a packed array.

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