STRtree is general at least twice as fast as Quadtree. Perhaps that's why it was chosen?
Sunburned Surveyor wrote: > I just completed my first code review of the JTin SoC project that > Chris Demars has been working on. I wanted to include the mailing list > on my comments to Chris, as I know there are more experienced > programmers listening that can offer Chris there own suggestions on > his design. > > I must say that Chris took an interesting approach to the design of > JTin, and one that was a lot different from the approach I would have > taken. However, I think Chris' design will be much quicker and more > memory efficient. His professional programming background is evident > in the work. I tend to get lazy when I program, creating objects for > every little thing. JTin looks like it was written by a C programmer. > All the data structures are concise and fairly low-level. > > Here are some of my questions and comments for Chris: > > - I like that the TinFace objects, braklines, and boundaries in > ImmutableTin points to a common Coordinate array to eliminated > duplicated Coordinate references. > Did you think about using a CoordinateSequence instead of a Coordinate > array? > > - Why did we choose STRtree and not QuadTree for the spatial index? I > know very little about both classes, and STRtree may indeed be the > better choice. Maybe Martin Davis will > take a few minutes to educate me. > > - Is the int in the first element of the int[][] triTable argument for > the ImmutableTin class constructor the identifier of the Tin Face, > while the in in the > second element is the ID of the vertex? > > - I'm not sure about storing the nieghbor TinFaces in the actual > TinFace object. I almost wonder if having a separate class to manage > TIN topology would be better. > For example, how do you set references to a TinFace object's > neighbors when creating the first TinFace in an ImmutableTin? I guess > you could go back and set the > neighbors for each TinFace after the TIN was constructed, but it > looks like your only constructor for this class requires int arguments > identifying the neighbors. > You probably have good reason for this design, I just didn't pick up on it. > > - Let's get that JTF format documented in JTFLayout class into an > external document, prefereably PDF or HTML. We can then introduce the > rest of the FOSS GIS community to the format. This will encourage > broad adoption of the format. > > Chris has done great work. I didn't go trough his code with a fine > tooth comb, as there is quite a bit of material there, but I look > forward to learning more about the library as I work with it. > > If others have a time to browse the JTin source I know that Chris and > I would both appreciate it. Please feel free to respond to my > questions and comments for Chris in this e-mail. > > Landon > > ------------------------------------------------------------------------- > Sponsored by: SourceForge.net Community Choice Awards: VOTE NOW! > Studies have shown that voting for your favorite open source project, > along with a healthy diet, reduces your potential for chronic lameness > and boredom. Vote Now at http://www.sourceforge.net/community/cca08 > _______________________________________________ > Jump-pilot-devel mailing list > Jump-pilot-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel > > -- Martin Davis Senior Technical Architect Refractions Research, Inc. (250) 383-3022 ------------------------------------------------------------------------- Sponsored by: SourceForge.net Community Choice Awards: VOTE NOW! Studies have shown that voting for your favorite open source project, along with a healthy diet, reduces your potential for chronic lameness and boredom. Vote Now at http://www.sourceforge.net/community/cca08 _______________________________________________ Jump-pilot-devel mailing list Jump-pilot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel
