hi bob, the problem with this is that I need an array first; that implies (if I understand correctly), that I have the entire file read into one array first (which is not feasible in my case); what I'm doing now, is for a given linear range (e.g. 1000th to 2000th element in the "flat data") I calculate small number of appropriate sections which will then when iterated one after another reproduce that exact linear range. best, .h.h. On 26/01/17 17:14, Bob Simons - NOAA Federal wrote: > Perhaps you could use one of the built-in iterators, such as > Array.getRangeIterator > <http://www.unidata.ucar.edu/software/thredds/current/netcdf-java/javadoc/ucar/ma2/Array.html#getRangeIterator-java.util.List->(java.util.List<Range > <http://www.unidata.ucar.edu/software/thredds/current/netcdf-java/javadoc/ucar/ma2/Range.html>> > ranges) > > On Thu, Jan 26, 2017 at 7:58 AM, Hanns Holger Rutz <rutz@xxxxxx > <mailto:rutz@xxxxxx>> wrote: > > hi there, > > for the record, i managed to implement an algorithm that solves > this ( > > https://stackoverflow.com/questions/41850946/linearly-reading-a-multi-dimensional-array-obeying-dimensional-sub-sectioning#41870662 > > <https://stackoverflow.com/questions/41850946/linearly-reading-a-multi-dimensional-array-obeying-dimensional-sub-sectioning#41870662> > shows how to generate the sub-ranges within the overall section to > be read ) > > best, .h.h. > > > On 25/01/17 12:20, Hanns Holger Rutz wrote: > > hi there, > > > > I have a scenario where I need to read the entire contents of a > > multi-dimensional section'ed variable piecewise linearly. > > > > for example, say the variable has shape [a][b][c] and I have > section'ed > > it as [s1][s2][s3]. say data type is double. now i need to read the > > stream of elements, the total size of which is s1.size * s2.size * > > s3.size in chunks, for example of chunk size x. > > > > the API for variable doesn't allow me to specify "flat" linear > indices, > > so I need to calculate intermediate sub-sections, I guess. this looks > > very complicated because the chunk size x might not be a simple > multiple > > of s3.size, s2.size*s3.size, etc. > > > > So I can only think of two approaches: read "too" much data and then > > throw away some. Read multiple times; perhaps this problem can be > > formulated in maximally three read calls? > > > > Has anyone solved this somehow? Or is there a trick in the API that I > > haven't seen, to get a linear read command that preserves the offsets > > and strides of sections? > > > > thanks, .h.h. > > > > _______________________________________________ > > NOTE: All exchanges posted to Unidata maintained email lists are > > recorded in the Unidata inquiry tracking system and made publicly > > available through the web. Users who post to any of the lists we > > maintain are reminded to remove any personal information that they > > do not want to be made public. > > > > > > netcdf-java mailing list > > netcdf-java@xxxxxxxxxxxxxxxx <mailto:netcdf-java@xxxxxxxxxxxxxxxx> > > For list information or to unsubscribe, visit: > http://www.unidata.ucar.edu/mailing_lists/ > <http://www.unidata.ucar.edu/mailing_lists/> > > > > > > _______________________________________________ > NOTE: All exchanges posted to Unidata maintained email lists are > recorded in the Unidata inquiry tracking system and made publicly > available through the web. Users who post to any of the lists we > maintain are reminded to remove any personal information that they > do not want to be made public. > > > netcdf-java mailing list > netcdf-java@xxxxxxxxxxxxxxxx <mailto:netcdf-java@xxxxxxxxxxxxxxxx> > For list information or to unsubscribe, visit: > http://www.unidata.ucar.edu/mailing_lists/ > <http://www.unidata.ucar.edu/mailing_lists/> > > > > > -- > Sincerely, > > Bob Simons > IT Specialist > Environmental Research Division > NOAA Southwest Fisheries Science Center > 99 Pacific St., Suite 255A (New!) > Monterey, CA 93940 (New!) > Phone: (831)333-9878 (New!) > Fax: (831)648-8440 > Email: bob.simons@xxxxxxxx <mailto:bob.simons@xxxxxxxx> > > The contents of this message are mine personally and > do not necessarily reflect any position of the > Government or the National Oceanic and Atmospheric Administration. > <>< <>< <>< <>< <>< <>< <>< <>< <>< > > > > _______________________________________________ > NOTE: All exchanges posted to Unidata maintained email lists are > recorded in the Unidata inquiry tracking system and made publicly > available through the web. Users who post to any of the lists we > maintain are reminded to remove any personal information that they > do not want to be made public. > > > netcdf-java mailing list > netcdf-java@xxxxxxxxxxxxxxxx > For list information or to unsubscribe, visit: > http://www.unidata.ucar.edu/mailing_lists/ >
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