Re: [netcdf-java] Reading "linearly" through a multi-dimensional array

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> 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
> 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.
> >
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>
>
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-- 
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

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.
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