hi bob, thanks -- i'm basically doing exactly that. the tricky bit was to calculate the "section or range" for an arbitrary linear range in the flat backing data. it works now based on the linked algorithm :) best, .h.h. On 26/01/17 17:28, Bob Simons - NOAA Federal wrote: > Okay, then > 1) variable.read(section or range) gives you an Array with a range's data. > 2) array.next() (or a variant) returns the next value from the array, > using the local iterator and array.hasNext() tells you if there is > another value available from the iterator. > > Every Array object has a built in "local iterator". See the Array > documentation for all the methods that use it. > > > > On Thu, Jan 26, 2017 at 8:17 AM, Hanns Holger Rutz <rutz@xxxxxx > <mailto:rutz@xxxxxx>> wrote: > > 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- > > <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 > > <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> > > <mailto: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> > > > > <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> > <mailto: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/> > > <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> > <mailto: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/> > > <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 <tel:%28831%29333-9878> (New!) > > Fax: (831)648-8440 <tel:%28831%29648-8440> > > Email: bob.simons@xxxxxxxx <mailto:bob.simons@xxxxxxxx> > <mailto: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 <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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