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“Alternative” Data Structures. Information Spaces / Spatialization. www.smartmoney.com. Information Spaces / Spatialization. Chen et al. 1998. Information Spaces / Spatialization. Information Spaces / Spatialization. Alternative Data Structures
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Information Spaces / Spatialization www.smartmoney.com
Information Spaces / Spatialization Chen et al. 1998
Alternative Data Structures (especially w/ increased processing speeds, storage)
they divide the space between the points as ‘evenly’ as possible market area delimitation, rain gauge area assignment, VIPs DTs are as near equiangular as possible, thus minimizes distances for interpolation elevation, slope and aspect of triangle calculated from heights of its three corners A A Thiessen (Voronoi) Polygonsand Delaunay Triangles Thiessen Polygons Delaunay Triangles Thiessen neighbors of point A share a common boundary. Delauney triangles are formed by joining points to its Thiessen neighbors.
• partition areas based on “influence” of sample points (Thiessen polys)• all sample points connected w/ 2 nearest neighbors to form triangles• connect centroids of Thiessen polygons market area delimitation, rain gauge area assignment, trusted elevation benchmarks or VIPs, etc.
Sampled locations and values Thiessen polygons Daniel P. Ames, Dept. of Geosciences (Geology), Idaho State University
Visualization of Theissen Concept Arthur J Lembo, Jr., Bowne
Inverse Distance Weighting Arthur J Lembo, Jr., Bowne
Kriging Arthur J Lembo, Jr., Bowne
TIN(Triangulated Irregular Network) • avoids redundancy of raster while still producing a continuous surface • more efficient than raster for some terrain analysis • slope and aspect (faces of triangles) • contouring • Measurements are irregularly spaced with more sampling in areas of greater complexity • requires fewer points or grid cells
Contours from TIN(triangles can be many and extremely small with a good sampling of points)
• Computers love rasters• A cell on 1 map is at same position on all others• Easy query, neighborhood ops., etc.
Compression:Run Length Encoding • based on spatial autocorrelation • nearby things tend to be more similar than distant things • data entered as pairs • run length & value • 40 items instead of 70
• way of encoding irregularity of vector in raster form• step beyond run-length-encoding compression• compress in row AND column directions
Quadtrees of Chloropleth Raster Map NW NE SW SE NW NE SW SE Marc van Kreveld, U. of Utrecht
Adaptive MWVD solution Rene Reitsma, OSU CoB • Vector solution: infinite precision, difficult computing. • Raster solution: limited precision, easy computing. • Resolution increases allow higher precision. • Boundary-only, quadtree resolution increases.
Gateway to the Literature“information spaces” • Reitsma, R. and Trubin, S., Information space partitioning using adaptive Voronoi diagrams, Information Visualization, http://www.palgrave-journals.com/ivs/, 2006. • Dodge, M., and R. Kitchin, Code and the transduction of space, Annals AAG, 95 (1), 162-180, 2005. • Fabrikant, S.I., and B.P. Buttenfield, Formalizing semantic spaces for information access, Annals AAG, 91 (2), 263-280, 2001. • Skupin, A., On Geometry and Transformation in Map-Like Information Visualization. In: Börner, K., Chen, C (Eds.) Visual Interfaces to Digital Libraries. Lectures in Computer Science 2539. Springer Verlag, Berlin. 161-170, 2002.
Gateway to the Literature“natural spaces” • Chen, J., C. Li, Z. Li, and C. Gold, A Voronoi-based 9-intersection model for spatial relations, Int. J. Geog. Inf. Sci., 15 (3), 201-220, 2001. - voronoi_ijgis.pdf • Chen, J., C. Qiao, and R. Zhao, A Voronoi interior adjacency-based approach for generating a contour tree, Comp. Geosci, 30, 355-367, 2004. • voronoi_contour_tree.pdf • Gold, C.M., and A.R. Condal, A spatial data structure integrating GIS and simulation in a marine environment, Mar. Geod., 18 (3), 213-228, 1995. • Mostafavi, M.A., C. Gold, and M. Dakowicz, Delete and insert operations in Voronoi/Delauney methods and applications, Comp. Geosci, 29, 523-530, 2003. - voronoi_2003.pdf • Zhang, H., and C. Thurber, Adaptive mesh seismic tomography based on tetrahedral and Voronoi diagrams: Application to Parkfield, California, J. Geophys. Res., 110 (B04303), doi:10.1029/2004JB003186, 2005. - seismic_mesh.pdf
Dynamic Segmentationmultiple attributes to a single arc...attribute to a portion of an arc...
Heceta Bank Fisheries InvestigationsM.S. Theses: Nasby, 2000; Whitmire, 2003 • At what scales are there quantifiable relationships between groundfish populations and seafloor morphology/texture? • What are the factors that control these relationships? • What changes may have occurred in the fish populations after a decade? • What are the characteristics and extent of natural refugia?
EM 300 Multibeam Bathymetry • Depth Range: • 60-1000 m • Gridded to 5 and 10 m Nasby, 2000; Whitmire, 2003
Dives • 28 ROV dives • 5 submersible dives • 6 historical stations Nasby, 2000; Whitmire, 2003
Heceta Bank Fish Habitats • Seabed Classification • Mud • Sand • Pebble • Cobble • Boulder • Flat Rock • Rock Ridge Nasby, 2000; Whitmire, 2003
Mud Sand Pebble Cobble Boulder Flat rock Rock ridge 1267 1269 1268 M = Mud S = Sand P = Pebble C = Cobble B= Boulder F = Flat Rock R = Rock Ridge Nasby, 2000
Bottom Type Whitmire, 2003
Species TypeDensity of Dover Sole Nasby, 2000
Other Fish Species Pygmy rockfish Shortspine thornyhead Greenstripe rockfish Rex Sole Sablefish Lingcod Yellowtail rockfish Nasby, 2000
Habitat Characterization Summary Rock ridge: yellowtail rockfish and juvenile rockfish Pebble/cobble/boulder: sharpchin rockfish, rosethorn rockfish, greenstripe rockfish and pygmy rockfish Mud: Dover sole, rex sole, sablefish and shortspine thornyhead Nasby, 2000
Segue to Terrain Analysis Whitmire, 2003
Thesis Downloads • Nicole Nasby, 2000 dusk.geo.orst.edu/djl/theses/nasby_lucas.html (alsopublished in 2002 issue ofFisheries Bulletin) • Curt Whitmire, 2003 dusk.geo.orst.edu/djl/theses/whitmire_abs.html