## Algorithms in GIS (cs3225): Schedule

Test grids here.

Here is a detailed schedule of the class, to be updated as the semester progresses:

 9/3 Class introduction. Lab: Unix warmup | Using make | Emacs and vim | C 101 | BasicsI | BasicsII Sean's unix tutorial. Programming 0 [max malloc()'ed memory] 9/8, 9/10 Spatial data models and representation. Raster and vector models. ata structures for meshes (winged-edge; half-edge). Slides: Data models and representation Programming 1 [read an ascii grid] (due Tue 9/15) 9/15, 9/17, 9/22 Lab: brief intro on rendering (terrains) with OpenGL 1.x. graphics1 | graphics1.tar Programming 2 [render an ascii grid 2d] (due Tue 9/22) Programming 3 (render grid 3d) (due Tue 9/29) 9/24, 9/29, 10/1, 10/6 Flow on terrains. Flow direction and flow accumulation. Flat areas. Watersheds. Drainage basins. Watershed partitioning and Pfafstetter hierarchy. Flooding. Slides: Flow | Flooding Programming 4 (flow direction and accumulation)) Project 1: Flooding. 10/8, 10/15, 10/20, 10/22 Visibility on terrains. Basic algorithm for viewshed. From the straightforward algorithm to a radial sweep. A detour through augmenting RB-trees. Visibility and horizons. Viewshed via a concentric sweep. Interpolation effects. Computing all viewsheds on grid DEMs. Slides: Visibility Project 2: Visibility. 10/29 Line simplification. The problem, its weak and strong versions. Douglas Peucker's algorithm. The Imai-Iri idea: Computing the smallest epsilon-approximation via the shortcut graph. Slides: (not yet..) 11/3, 11/5 Terrain simplification. Slides: Terrain simplification Reading: Fast polygonal approximations of terrain and height fields (Garland and Heckbert 1995) | Garland's Terra, Scape, QSlim | Jonathan Shewchuck's website; Project 3: Simplification 11/10 Quadtrees. Slides: Quadtrees 11/12 Invited lecture: Using ArcGis in EOS, by Eileen Johnson, EOS. 11/17 Space-filling curves. Slides: Space-filling curves 11/19 Paper reading. Approximating the Visible Region of a Point on a Terrain (Ben-Moshe, Carmi and Katz, ALENEX/ANALCO 2004) | questions 11/24 Paper reading. Visibility preserving simplification(Ben-Moshe, Katz, Mitchell, Nir, SoCG 2002) 12/1 Project 3. 12/3 Project 3. 12/8 Project 3. 12/10 Project 3.