Hei Andreas, as Michael pointed out: we will try to support you. And having a 3d person working on it - should be ok. At least he is firm with all the 3d coordsys stuff. Working with ellipsoids is still a bit different but learnable. I am glad that Michael has also some experiences on that too..
stefan Andreas Schmitz schrieb: > Michaël Michaud wrote: > > Hi, > >> Making a new projection library is a very exciting project. >> As there are at least two other projects (javaproj and geotools) I'd >> like to make sure I undersand what would be the specific purpose of a >> new library. >> Javaproj and geotools have very different approaches (opposite ?), the >> first being very procedural (mainly math functions), and the second very >> object oriented (with a design based on OGC UML diagrams and GeoAPI >> interfaces). >> What would be the specific target of a third library ? >> I must admit that I'd like to see a complete lightweight library >> (including datum transfo, coordinate system transfo, and the capability >> to add complex transformations). I can't say if there is a better >> solution than geoapi/geotools. A few years ago, I felt geotools api was >> very complex and enable to solve the problems I had with some special >> transformations (french grid-based datum transformation), and I tried to >> design a new small library you still can find here : >> http://michael.michaud.free.fr/geodesie/JTransfoCoord.html >> I'm not completely satisfied with it and today, I would hesitate between >> a shift to geotools or a rewrite of this library. >> But in any case, I would be pleased to participate and to help with any >> project with the aim to incorporate projection stuff into OpenJUMP :-) > > That's good to hear :) > > When the time is ripe and our library usable, I'd also help > integrating it, of course. > > As to the other libraries (geotools etc), I'm not sure where the > deegree projection library fits in. I guess that depends a lot on how > much time can be put into this. From my (admittedly VERY narrow) point > of view it shouldn't be too difficult to implement a database based > approach that can transform between different types of coordinate > systems (like proj4) in Java, at least for the common types. But then > I read Stefan's comment ;-) > >> Stefan Steiniger a écrit : >> >>> Hei Andreas, >>> >>> thats good to hear. >>> I hope you are looking on geotools projection code as well. As far as i >>> checked out the guy that is responsible for it has the appropriate >>> background (at least i think so). and geotools realized already lots of >>> projections ( i guess EPSG completely). But lots of stuff needs to be >>> replaced. >>> Just a question: do you have a person with proper math-geodesy >>> background on projection stuff? (or a contact to Bonn University on >>> that: i.e. someone of the team of Prof. Karl-Heinz Ilk?) > > It's a computer scientist working on it. He's more into 3D, but he's > also quite firm in math, I believe ;-) > >>> I ask, because projections are a realy nasty thing. It is very important >>> to have appropriate testing data (e.g. to check the conversions to >>> WGS84). (btw: I did some software evaluation on Cadcorp SIS for Finnish >>> projection - which is to complicate for them, Swiss projection (also >>> some special formulas) and German GK/UTM projections). >>> It is somehow "satisfying" to hear that you plan to work on the >>> projection support implementation for 1-2 years (not just a month). I >>> think the "design" itself is also quite tricky, because later on the >>> user must be able to define its own coordinate system (beside the EPSG >>> ones). So it is good to look how ArcGIS, Cadcorp SiS, MapInfo, and so on >>> have realized the user interfaces and customization. > > Yes, that's definitely true. I think my company tried a lot of > different approaches to the problem during the past years, and none > were satisfying (else we wouldn't try a new one...). > > Best regards, Andreas ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Jump-pilot-devel mailing list Jump-pilot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel
