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RE: [udig-devel] Eclipse framework comments
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Hi Jacques, Everybody,
I too have been working on raster code, but not in any integrated way. I
have been processing SRTM data for testing a lot of metrics calculations
to generalise and classify surface regions. Sadly, the file format I use
to interchange is ESRI asciigrid, not netCDF or GeoTiff. What I guess I
do that is special is handle and process 2D Square Celled Raster Data
that have hundreds of thousands of rows and columns by catching memory
problems and hadnling the swapping of chunks of data. I am grid enabling
this software. Is there any interest yet in integrating this code with
GeoTools?
http://www.geog.leeds.ac.uk/people/a.turner/src/andyt/java/grids/
Best wishes,
Andy
A.G.D.Turner@xxxxxxxxxxx
http://www.geog.leeds.ac.uk/people/a.turner
-----Original Message-----
From: udig-devel-bounces@xxxxxxxxxxxxxxxxxxxxx
[mailto:udig-devel-bounces@xxxxxxxxxxxxxxxxxxxxx] On Behalf Of divol
Sent: 13 October 2005 12:22
To: User-friendly Desktop Internet GIS
Subject: Re: [udig-devel] Eclipse framework comments
preamble :
1/ i love to mix seriuous matter with fun.
2/ my sense of fun is disgusting
3/ my english is worst
:)
lets' begin
Since june 2005, i am playing with udig stuff.
so i could add some, how to say, battlefield experience maybe, about
how to begin with the fun of udig.
I am French (call me Jacques) and currectly using MacOS tiger, all
very bad, i know... but don't hurt me even for my "continental english".
I was a lazy user of Eclipse as i prefered, still today, Project
Bulder and knew nothing about GIS (just iso 19115) and was not a user
of gis tools and apps (the worst case i am affraid)
So, if you want to use udig
First step : know yourself
- be at ease in java (obvious but but ...)
- know what Design Pattern is (less obvious). A book was available
free on Sun site and OO programing in general (I am currently
learrning Obj-C Cocoa too...)
-get some notion of GIS software and map making (you can''t imagine
the work to draw iso lines, i just discovers that last week )
Second Step : know eclipse
-as user,
-as programner : udig uses eclipse plugin engine so it's important
to understand how it's work before. Eclipse uses a new UI framework
(SWT its name)
there's many sample and resources on the eclipse site (IBM site too)
and there's books, i am using Professional Eclipse 3 for java
Developper (Berthold Daum (english Edition :WROX, 2004) (french
Edition :Dunod) and (orginal german Edition: dpunkt.verlag GmbH
Heildelberg)
pre Third step : have a look on JAI, the source code is available on
sun site
Third step : udig use JTS libs for topology, Geotools, GEOAPI, ....
have a look and don't forget to get the source code in order to
understand.
sadly many classes havee the same name but no relationship... and try to
found the right distance() function !!!, a must do !
(it's here DefaultEllipsoid.WGS84.orthodromicDistance ...
i implemented : haversine, distVincenty, distCosineLaw before i found
orthodromicDistance ...
pre fourth : verify that your Eclipse is up to date and check
regulary for new version (the udig task force uses a very uptodate
eclipse :)
fourth step : Follow ALL the recommendation in order to install udig
source code via svn, even the words written in little, even those not
writen because you enter a world related to Terry Pratchet DiskWorld !!
- ok i joke...)
i prefere to use svn as command line or ((turtoise on windows) , the
plugin is somewhat surprising sometime.
and be aware, sometime the svn trunk, is not usable so try again the
next day... (the gentle guys warns... sometime as there's not all the
time on the stuff)
for that you must register to the udig mailing list (gentle guys but
i detected no girls sorry :(()
fiffth step : have fun !
as a matter of fact , when you add your code into udig (not stable )
based on libraries not finished (geotools/geoapi) don't forget : -your
pills -stay calm -DON'T PANIC as stated on H2G2 book you should read
-and don''t hurt yourself and your familly, its just code.
i took me 3 weeks from JAI codec to udig rendering to manage SRTM
DEM hgt file format a VERY simple and basic way, (pfff)
and i am not using AbstractRaster stuff as it will change
i am currently playing with JAI OperationDescriptor and code : Slope,
FlowDirection,...
(i also made tools, views, actions, commands, preferences,...)
WARNING : too often Exceptions are hidden and you get no
info ,sometime a nullpointerexception no more.
so during the developpement phase, trace your code and add explicite
try catch
it's hell to debug the georesource, serviceextension serviceimpl thru
the can_resolve runtime flow ....
WARNING : Don't abuse the Clean all, sometime it's could download the
whole new libs from udig repos, just the libs of course not the
code .... if there's no change into the API, no problemo. IffAPI
changes, you'ld need to update the udig code from trunk (sometime
it's not the good moment, speaking of experience)
feel free to trash this mail
jacques divol
IRD/US-ESPACE/CASH
divol@xxxxxxxxxxxxxxxx
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