A type of cartographic generalization in which the important characteristics of features are determined and unwanted detail is eliminated to retain clarity on a map whose scale has been reduced.

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90 views

PostGIS: How to dissolve vector data

I have a few scenarios where I need to dissolve vector data, and I'm wondering how to do this using PostGIS. What would the queries look like to perform these operations? Below I'll describe the ...
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1answer
105 views

Reduce number of points, keeping most recent data within a given distance

I have a HUGE dataset of points that were collected along a route. The data may change daily, and the most recent data is the most important. What I would like to do is take only 1 point from a given ...
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1answer
69 views

ArcGIS Raster To Multipoint Mac/OSX alternative

Is there an alternative to the ArcGIS Raster To Multipoint tool for Macs? The VIP thinning method is particularly of use. A comparative point cloud thinning/simplification tool to this would just as ...
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94 views

Simplify table of linestrings

I have a PostGIS table of linestrings representing a road network. I want to simplify the geometries such that only lines that connect road junctions are stored. At the moment the table has a large ...
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0answers
192 views

How do I simplify the straight sections of (multi)Linestring in PostGres/PostGis leaving the curved sections untouched

I have (multi)linestrings containing upwards of 5000 points and I want to perform two simplifications possibly using Ramer Douglas Peucker or alternative methods in PostGis The (multi)linestrings ...
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0answers
33 views

C/C++ function to return minimum set of points required to represent a geometric shape

I am looking for a method from Grass, GEOS, or similar that will delete those points in a geometry which do not affect its shape. Example 1 +----+----+ p0 p1 p2 p1 can be deleted without ...
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0answers
31 views

Combine files in TopoJSON when one is simplified differently to the other

I have two .shp files, I am separately converting these to GeoJSON with ogr2ogr.exe and then combining the files with TopoJSON. Each file independently becomes a ~200kb topojson file, however the ...
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0answers
537 views

Smooth, not simplify, lines features in PostGIS

I'm trying to automatically generate paths to place labels on that follow the shape of rivers, 4wd tracks and other very windy lines. At first I thought the st_simplify() function was the answer, but ...
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0answers
48 views

Resolve Building Conflicts - the open source way?

In ArcGIS there is a tool called Resolve Building Conflicts and I'd like to achieve the same using only open source tools (QGIS, GDAL etc), preferably on Mac OS instead. In the long run I'm trying to ...
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0answers
66 views

Query to merge simplified polygons according to the map scale-factor

I'm trying to construct a view in PostgreSQL that simplify polygons according to the map scale-factor. Basically I was reading this thread ...
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0answers
45 views

QGIS - Simplification process creates a new polygon - how to avoid it?

I am trying to simplify a layer made of polygons. I have used different methods but the new simplified layer has a polygon which intersect with itself, thus creating a "new" polygon. Please see ...
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0answers
32 views

Keep synchronization when simplify features from different data source

We have two shapfile data source: 1 water-riverbank.shp With geometry type of Polygon which stands for the area of water 2water-riverline.shp. With geometry type of LineString which stands for ...
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0answers
314 views

How to import large features to Google Fusion Table from KML?

I am trying to import rather large features to Google Fusion Table from KML files (I have also shapefiles). However, Google has a certain limitation: "a cell of data in Fusion Tables supports a ...
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0answers
406 views

How do I smooth edges of polygons in QGIS?

Is there a built in function or plugin I can use to achieve smooth lines for my polygons instead of the blocky ones I have now?
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0answers
118 views

Simplify by number of points in QGIS

I have a fairly simply question about something I just don't know how to do. I am aware you are able to simplify polygons in QGIS based on distance tolerance but my questions is, is there a way to ...
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0answers
27 views

Draw (adjacent) GIS-shapes, reduced and “rounded”

as the title says: I want to draw (C#, WinForms application) adjacent polygons stored in an GIS-database (SQL Server 2012, geography-datatype). The data source is OpenStreetMap administrative ...
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0answers
83 views

Reducing point numbers in a certain area

We have a list of poi data in our database(Access mdb db), and we have a web service which serve data by a specified BoundingBox. However we found that the returned points are too close to another at ...
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135 views

Can I simplify polygons in QGIS by Size?

Just wondering if it's possible in QGIS to simplify polygons based on size? I've done it many times using the tolerance level to reduce the overall size however in this case each polygon cannot be ...