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04a19024f1
git-svn-id: http://svn.osgeo.org/postgis/trunk@3572 b70326c6-7e19-0410-871a-916f4a2858ee
103 lines
4.1 KiB
Plaintext
103 lines
4.1 KiB
Plaintext
$Id$
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== Simple Projects ==
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* ST_IsMeasured(geometry)
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TRUE or FALSE depending on existence of M
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* ST_LocateAlong(reference geometry, measure float)
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* ST_LocateBetween(reference geometry, start float, end float)
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* ST_CleanGeometry(geometry)
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Attempt to make invalid geometry valid
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* ST_SplitGeometry(polygon, line) returns components of polygon
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* ST_SplitGeometry(lineA, lineB) returns components of lineA
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* ST_SplitGeometry(line, point) returns components of line
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* ST_Hausdorf(g1 geometry, g2 geometry) returns double.
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Need to get def'n from JTS.
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* ST_AverageDistance(g1 geometry, g2 geometry, nsamples integer) returns double
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Sum of minimum distances at regular intervals up two geometries,
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divided by the number of samples.
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* ST_MaxDistance(g1 geometry, g2 geometry) returns double.
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What is the maximum distance between these two geometries.
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* ST_GeomFromKML(string) returns geometry. Ingests KML geometry parts only.
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* ST_GeomFromGML(string) returns geometry. Ingests GML geometry parts only.
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* ST_GeomFromGeoJSON(string) returns geometry. Ingests JSON geometry parts only.
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* ST_LatitudeFromText(string) returns float,
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LongitudeFromText(string) returns float
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for things like 132W 23' 23", or 45N 23.41232', or 123.14123W, etc, etc, etc.
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* ST_AsLatLonText(<point>, [formatstring]) returns string.
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Format string could use DD DD.DD MM MM.MM SS SSSS.SSS style
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tokens and allow anything else (E, W, ", ', degree sign)
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to be interleaved within.
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* ST_DumpPoints(g1 geometry) returns setof geometry_dump
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Similar in concept to ST_Dump and ST_DumpRings will output a
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geometry_dump array for any geometry where each geometry is a point
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and path info to denote the locaiton/subgeometry it is located in.
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== Larger projects ==
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-- Complete Curve support --
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The LWGEOM construct does not have quite enough space to hold all the
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typology variants of curves. And it certainly doesn't have enough space
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for encoding the line interpolation type.
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Complete curve support would require re-working all the way back into
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GEOS to support non-linear interpolations in all GEOS calculations,
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and may never get done.
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Intermediate curve support requires handling all curve types and stroking
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them into linear interpolations for hand-off to GEOS functions. Inexact
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but providing some utility.
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Current curve support does include indexing and in/out functions but needs
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much better documentation, particularly about the valid WKT and WKB forms.
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-- Geodetic support --
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A new "geography" type which is indexed in cartesian 3-space, possibly
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using direction cosines as the ordinates, and supports some basic functions,
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most importantly, distance on all types, area on all types and an
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intersects predicate. Casts back to "geometry" could allow use with
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standard functionality.
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-- Topology --
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Expand on the existing topology experiment, in particular buiding topologies
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from existing POLYGON and MULTIPOLYGON "coverages" (simple feature collections
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that have an expectation of no overlaps or gaps).
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-- GEOMETRY_COLUMNS --
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Add the maintenance of GEOMETRY_COLUMNS to the "ANALYZE" operation, so that
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an ANALYZE automatically removes orphaned rows from GEOMETRY_COLUMNS and
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adds entries for new rows.
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-- typmod support --
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Allow geometry(srid, type) constructors to automatically fill out GEOMETRY_COLUMNS and constraints.
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-- Estimated Extent --
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Fast extent estimation based on reading the head of the R-Tree.
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-- Nearest Neighbor --
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Fast nearest neighbor searching based on traversing the R-Tree.
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See,
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http://citeseer.ist.psu.edu/roussopoulos95nearest.html
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http://citeseer.ist.psu.edu/91356.html
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-- Heat Map / Clustering --
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Given a set of points, generate a heat map output. Or, given a set of points, generate a clustering and set of representative points. In general, extract a trend from a collection.
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== Breaking Changes ==
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* Convert the "default SRID" from -1 to 0
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* Convert the LWGEOM struct(s) to have enough padding that the coordinates
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are double-aligned and can be accessed directly as doubles on all
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architectures
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* Support all typologies of EMPTY (POINT EMPTY, LINESTRING EMPTY) instead
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of just using GEOMETRYCOLLECTION EMPTY all the time.
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