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Posted to dev@sis.apache.org by Martin Desruisseaux <ma...@geomatys.fr> on 2013/02/22 13:38:56 UTC

RangeSet, and work for volunteer (if any)

Hello all

The recently committed RangeSet class was the last part of Range-related 
classes. The main use case is to represent the range of available data 
in a time series, and the holes where data are missing. Imagine for 
example a time series for thousands of remote sensing images, each image 
being representative on one week (e.g. NOAA's AVHRR data). A developer 
can use a loop for inserting the temporal Range of each images in a 
RangeSet. Overlapping ranges are merged, which should result in a single 
large range covering for instance 10 years of data. But if there is some 
holes (some weeks without data), then the RangeSet will contains two or 
more Range instances, with the time of missing data between the ranges. 
This make easy to spot holes by examining the RangeSet content, or to 
display it in a widget.

However for licensing reasons, the implementation of 
RangeSet.remove(E,E) method has not been ported. If there is any 
volunteer for implementing that method, I have filled a JIRA task for 
this purpose:

https://issues.apache.org/jira/browse/SIS-79

     Martin


Re: RangeSet, and work for volunteer (if any)

Posted by Martin Desruisseaux <ma...@geomatys.fr>.
Le 22/02/13 22:30, Joe White a écrit :
> Chris, you read my mind. I'm supposed to be back in Atlanta on Sunday
> night, so I can look into it on Monday.

Thank you very much Joe!

I also wonder... would you be eventually interested to contribute to 
GeoAPI [1] too? This is not exactly SIS, but closely related since SIS 
aims to be a GeoAPI implementation. Scope would be eventually larger, 
since - if GeoAPI has some success - it would hopefully be implemented 
by more software than just SIS. It is a "kind of work" slightly 
different than SIS, in that SIS is more about extensive coding, while 
GeoAPI is more about looking carefully to international standards. 
GeoAPI is an Open Geospatial Consortium (OGC) working group, but 
volunteers can contribute without being OGC member since the SVN 
repository is hosted by SourceForge. However most GeoAPI work has to be 
given OGC copyright, but the license is BSD-like.

One GeoAPI work that I'm thinking about is the "Geospatial integrity of 
geoscience software (GIGS)" [2] test suite. GIGS tests were created by 
the authors of the EPSG database (a very important piece of information 
in a SIS). Those tests are provided as Excel documents. In GeoAPI, we 
started to implement them as JUnit tests [3]. We ported the series 2000 
and series 3000 tests, but more series need to be ported. Libraries like 
SIS inherit automatically those test suites, so GeoAPI tests could be 
used for making comparative analysis of correctness of different 
geographic software (I think it could be a nice FOSS4G presentation - we 
will be able to compare SIS with Proj.4).

However one inconvenient is that Apache SIS is not yet able to run those 
GIGS tests. If you were working on GIGS tests and wanted to try them, 
you would have to test with the Geotk library for now (a LGPL library 
which is the source of the code ported and relicensed to Apache)... It 
would be a temporary situation, since my goal is to finish porting the 
Geotk referencing module (and hopefully more than just that module) 
before the Nottingham FOSS4G meeting. However I think it is perfectly 
normal if you prefer to focus on SIS, so GIGS tests are really just an 
idea that I tell just in case.

     Regards,

         Martin

[1] http://www.geoapi.org/
[2] http://www.epsg.org/gigs.html
[3] 
http://www.geoapi.org/geoapi-conformance/apidocs/org/opengis/test/referencing/gigs/package-summary.html


Re: RangeSet, and work for volunteer (if any)

Posted by Joe White <wh...@gmail.com>.
Chris, you read my mind. I'm supposed to be back in Atlanta on Sunday
night, so I can look into it on Monday.

Joe
On Feb 22, 2013 4:18 PM, "Mattmann, Chris A (388J)" <
chris.a.mattmann@jpl.nasa.gov> wrote:

> Thanks Martin.
>
> I'll be at ApacheCon NA 2013 next week but perhaps during that time can
> take a look.
>
> Otherwise, Joe White was around before looking for a way to contribute,
> Joe this may be a cool way :)
>
> Cheers,
> Chris
>
> On 2/22/13 4:38 AM, "Martin Desruisseaux"
> <ma...@geomatys.fr> wrote:
>
> >Hello all
> >
> >The recently committed RangeSet class was the last part of Range-related
> >classes. The main use case is to represent the range of available data
> >in a time series, and the holes where data are missing. Imagine for
> >example a time series for thousands of remote sensing images, each image
> >being representative on one week (e.g. NOAA's AVHRR data). A developer
> >can use a loop for inserting the temporal Range of each images in a
> >RangeSet. Overlapping ranges are merged, which should result in a single
> >large range covering for instance 10 years of data. But if there is some
> >holes (some weeks without data), then the RangeSet will contains two or
> >more Range instances, with the time of missing data between the ranges.
> >This make easy to spot holes by examining the RangeSet content, or to
> >display it in a widget.
> >
> >However for licensing reasons, the implementation of
> >RangeSet.remove(E,E) method has not been ported. If there is any
> >volunteer for implementing that method, I have filled a JIRA task for
> >this purpose:
> >
> >https://issues.apache.org/jira/browse/SIS-79
> >
> >     Martin
> >
>
>

Re: RangeSet, and work for volunteer (if any)

Posted by "Mattmann, Chris A (388J)" <ch...@jpl.nasa.gov>.
Thanks Martin.

I'll be at ApacheCon NA 2013 next week but perhaps during that time can
take a look.

Otherwise, Joe White was around before looking for a way to contribute,
Joe this may be a cool way :)

Cheers,
Chris

On 2/22/13 4:38 AM, "Martin Desruisseaux"
<ma...@geomatys.fr> wrote:

>Hello all
>
>The recently committed RangeSet class was the last part of Range-related
>classes. The main use case is to represent the range of available data
>in a time series, and the holes where data are missing. Imagine for
>example a time series for thousands of remote sensing images, each image
>being representative on one week (e.g. NOAA's AVHRR data). A developer
>can use a loop for inserting the temporal Range of each images in a
>RangeSet. Overlapping ranges are merged, which should result in a single
>large range covering for instance 10 years of data. But if there is some
>holes (some weeks without data), then the RangeSet will contains two or
>more Range instances, with the time of missing data between the ranges.
>This make easy to spot holes by examining the RangeSet content, or to
>display it in a widget.
>
>However for licensing reasons, the implementation of
>RangeSet.remove(E,E) method has not been ported. If there is any
>volunteer for implementing that method, I have filled a JIRA task for
>this purpose:
>
>https://issues.apache.org/jira/browse/SIS-79
>
>     Martin
>