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4

For example: let's say you have a 10 megabyte raster/vector file that covers a large area. If you include the file directly into OpenLayers, it will download the entire file to the browser and render whatever part of it the map needs even if it's a small area. What mapserver will do for you is always deliver to the browser a small image of exactly what ...


4

EDIT: Update, having belatedly realized this is a Map Server question. In general, to get the convex hull, you will want to group by id/gid, as producing the hull(s) is an aggregate operation. So, without the Mapserver part, the query would look like: SELECT id, ST_ConvexHull(ST_Collect(the_geom)) as the_geom from xyz group by id; Now, to get MapServer ...


3

How about using GDAL_Grid? Just pass the arguments over to GDAL and return the raster file or render it in the web browser. It does IDW, Nearest neighbor, and averaging and has a robust set of input parameters.


3

Step-by-step for GeoServer. Note: As @michal-mackiewicz writes, the WPS extension for GeoServer must be installed. Acquire some point data, for example Natural Earth populated places http://www.naturalearthdata.com/http//www.naturalearthdata.com/download/10m/cultural/ne_10m_populated_places.zip Import data into Postgis for example with ogr2ogr ogr2ogr ...


2

Turns out it is as easy as this: MIMETYPE "application/json; subtype=geojson; charset=utf-8" Without the setting, no content encoding is returned by the server.


2

Thinking that you need heat maps rendered on the fly, I would go for these options instead: Leaflet: http://www.patrick-wied.at/static/heatmapjs/example-heatmap-leaflet.html OpenLayers: http://www.websitedev.de/temp/openlayers-heatmap-layer.html Both LL and OL: http://www.patrick-wied.at/static/heatmapjs/examples.html Some on-the-fly examples: ...


2

With MapServer the pixel value of a raster layer that should be interpreted as "nodata" and which should therefore be transparent is defined in the LAYER section of mapfile with the OFFSITE parameter. This is explained in MapServer documention at http://mapserver.org/mapfile/layer.html?highlight=offsite%20raster.


1

I found the solution, it basically was to change this: -DCMAKE_LEGACY_CYGWIN_WIN32=1 to -DCMAKE_LEGACY_CYGWIN_WIN32=0 so, I used: cmake .. -DWITH_OGR=0 -DWITH_GDAL=0 -DWITH_WCS=0 -DWITH_WFS=0 -DCMAKE_LEGACY_CYGWIN_WIN32=0 and Mapserver compiled flawlessly.


1

If security is not an issue but you only want to load data within the current viewport. You can also look at OpenLayers BBOX strategy.


1

To investigate an error in a script file with psql, it may help to identify the first error by stopping the script on the first error with: \set ON_ERROR_STOP on This is off by default, which is why you might see repeated noise messages "ERROR: current transaction is aborted, commands ignored until end of transaction block" With an error like: ...


1

From a clean Ubuntu 12.04 Precise install I was able to get it to work with this: echo 'deb http://ppa.launchpad.net/ubuntugis/ppa/ubuntu precise main' | sudo tee -a /etc/apt/sources.list echo 'deb-src http://ppa.launchpad.net/ubuntugis/ppa/ubuntu precise main' | sudo tee -a /etc/apt/sources.list sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys ...


1

Geoserver can render a heatmap from vector points using Rendering Transformations. For this feature to work, you will have to install WPS Extension (but WPS service doesn't need to be enabled).



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