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2

For PostGIS 2.1, you can just convert the geometry to a geography type, where longitudes are always normalised to the -180/+180 range. For example, take these coordinates that are outside the range, and compare the normalised output: SELECT ST_AsText(geom::geography::geometry) FROM (SELECT 'POLYGON((180.12 -16.69,180.00 -16.80,179.89 -16.95, ...


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You can use ST_DumpPoints and iterate over its results. It should be exactly what you're looking for.


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Why don't you just save the edits to your wfs-t? If you don't have to use Mapserver you could for example use Geoserver to publish your services and save your edits and users could download the layer directly from Geoserver as shapefiles. ...


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You can not magically create islands out of the points you have. Any algorithm will struggle, as even if you can work out a way to automatically separate the points into distinct islands, you wont know what order to join the points in. Unfortunately, I suggest that you manually create the islands. You can do this in QGIS with snapping to your points, so ...


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OpenLayers runs in the browser, and does not provide a method for generating shapefiles. What I would suggest is generating GeoJSON of your drawn featurres and POSTing that to the server, where you can use your language of choice to generate a shapefile from the GeoJSON.


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For this I would project first into a Projected Coordinate System that uses units of meters. Then if you have an ArcInfo/Advanced level license use the Point Distance tool: Determines the distances from input point features to all points in the near features within a specified search radius. Alternatively, look at Performing Point Distance analysis ...


3

You don't need to create an extra field to do this. I can see the arcgis-desktop tag in the question. So the workflow in arcgis desktop is of the following: 1- Make a selection (Dates Over 2013) and export to a separate shape file. 2- Revert the selection and export to a separate shape file. Snapshots in ArcGIS:


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If you want to get the distance between two sets of lat/lon, 4326, points, then you can use ST_Distance_Sphere or for more accuracy, ST_Distance_Spheroid. If your fence table is in 900913, then use, ST_Transform to convert, so that both sets of points are in a common SRID. SELECT ST_Distance_Sphere( (select ST_Transform("Fence", 4326) FROM ...


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Arcobjects: IPolygon polygon = (IPolygon)geometry; IPointCollection pointCollection = (IPointCollection)polygon;


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In QGIS to convert a polygon into a point you would use the Polygon Centroids tool. This is found under Vector>Geometry Tools>Polygon Centroids... This will also preserve attributes and puts the point in the geometric centroid of the polygon. Edit: For points around the perimeter, you will want, as mentioned, Vector>Geometry Tools>Extract Nodes... This ...


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If you are comfortable with Python you only need classic Python, list comprehensions and the understanding of PyQGIS: Geometry Handling: A Point in PyQGIS is built with QgsPoint(x,y); A LineString with QgsGeometry.fromPolyline([QgsPoint(x1,y1),QgsPoint(x2,y2)])) A Polygon with QgsGeometry.fromPolygon([[QgsPoint(x1,y1),QgsPoint(x2,y2), ...


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You can take the extractPoints() function from the fTools plugin by Carson Farmer: # Generate list of QgsPoints from input geometry ( can be point, line, or polygon ) def extractPoints( geom ): multi_geom = QgsGeometry() temp_geom = [] if geom.type() == 0: # it's a point if geom.isMultipart(): temp_geom = geom.asMultiPoint() ...


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I found a simple work around: Use ET Geowizards - Points - Create Station Points to station the line in increments smaller than the distance between data points. The created points (Sample1) will be in numerical order. Join (using spatial location) the Sample1 data points to the data set that you want to re-order. For question 2 in dialog box, choose ...


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you can use linear referencing to extract the position of the points along the lines ("locate along route" tool). Then you sort your point using these values and compute an incremental integer.


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Have you looked at a Spatial Join? Here is the Esri Help on the tool: http://resources.arcgis.com/en/help/main/10.2/index.html#//00080000000q000000 The tables of the three point features will be joined together based on the spatial relationship you specify.


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In ArcGIS, this can be done with Create random point if you have spatial analyst or 3D analyst or Advanced(ArcInfo) licence select each shapefile as "constraining_feature_class" and set the "minimum_allowed_distance"to 250 m. Otherwise the workaround is to create a loop in Python to add one random point, keep if it match your need (select by location) ...



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