Hi Rob, thanks for your reply.
On Wed, Apr 6, 2011 at 1:39 PM, Rob Latham <[email protected]> wrote: > On Tue, Apr 05, 2011 at 01:55:36PM -0400, Kai Germaschewski wrote: > > So, on proc 1 want to say: > > > > append hyperslab(filespace, <block1>) > > append hyperslab(memspace, <block1>) > > append hyperslab(filespace, <block4>) > > append hyperslab(memspace, <block4>) > > append hyperslab(filespace, <block3>) > > append hyperslab(memspace, <block3>) > > Is H5Sselect_hyperslab with H5S_SELECT_OR not sufficient? > Unfortunately, no, because that does not preserve the ordering I need. (I actually tried it, even, but as I suspected, "OR" is commutative but for me the order matters.) Actually, I think there's even a non-parallel case where the current interface is too limiting for me (well, there might well be another way of doing it, like defining a datatype for an entire block and then doing a list of such block "points".): file proc #1 +----+----+ +------+ |1111|2222| |......| |1111|2222| |.1111.| +----+----+ |.1111.| |......| +------+ |......| |.2222.| |.2222.| |......| +------+ In this case, it doesn't even matter whether one selects the filespace with two OR's or just everything in the first place, the order is going to be row-by-row "11112222" in the file, and obviously that's not the case in the memory space, where you first get all of one block, then the other (I'm a C programmer, but I maintain my fields in Fortran order, if that confuses you just transpose the global field in the file space and the blocks in memory.) If the two blocks lived on separate procs, everything would be fine, but handling the case of more than one block per processor needs something like a concept of a list of hyperslabs as opposed to a union of hyperslabs. --Kai -- Kai Germaschewski Assistant Professor, Dept of Physics / Space Science Center University of New Hampshire, Durham, NH 03824 office: Morse Hall 245E phone: +1-603-862-2912 fax: +1-603-862-2771
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