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Questions tagged [generalization]

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23 questions with no upvoted or accepted answers
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3
votes
2answers
129 views

Automatically fill gaps and merge freshly generated polygons with the longest adjacent polygon

I get polylines automatically generated from AutoCAD from a colleague. Converting them into polygons with QGIS 3.6, I find out some sliver polygons and gaps in between, as shown in the picture below : ...
3
votes
0answers
157 views

How to accelerate v.generalize on massive vector data?

I have a big problem with my vector dataset (more than 1 million entities) and v.generalize in grass 7.0.5 and 6.4 (64 bits for both). I try to use Douglas method on this dataset but it is very very ...
2
votes
0answers
49 views

Wang's Bend Simplify in QGIS

I am looking for an alternative to ESRI's Simplify Polygons - Bend Simplify method (I only have a Basic License). Is there an existing QGIS plugin which supports this specific polygon simplifying ...
2
votes
0answers
64 views

Generalizing / simplifying multipolygon in PostGIS without missing polygons?

By following the rules from this site, I got the output but some polygons do not come within the simplified polygon. I think the problem is with topology. Is there any solution?
2
votes
0answers
23 views

Conditional Expanding in ArcGIS Desktop?

I would like to reclassify a LC map given some conditional rules (raster with 8 classes total). Using the illustration, I would like to expand the green pixels (two distinct classes) on the white ...
2
votes
1answer
126 views

Display multiple lines as one line in QGIS

I am working with the OSM Dataset and can´t find a way to display rails in a proper way. In a big scale the rails are displaying fine but as soon the lines begin to overlap in a smaller scale I don´t ...
2
votes
0answers
184 views

Building footprint polygon simplification / generalisation

I'm looking for implementations of polygon simplification algorithms that preserve topology and overall rectilinearity. The input data is building footprints which often have squarish protrusions and ...
2
votes
0answers
68 views

Avoiding edges using GRASS generalization?

I'm trying to process the national wide land cover data into vector polygons. In order to be quick I separate the data into several tiles and process them in parallel. process flow is : 1. v.in.ogr ...
2
votes
0answers
217 views

Is there a way to build topology and work with topology relations in PyQGIS?

Is there a way to build topology and work with topology relations in PyQGIS? I'm asking because I need to run some custom generalization algorithms on my data, and I need to preserve topology. ...
1
vote
0answers
80 views

How to generalize shape with PyQGIS without much Distortion in the shape?

I was trying to generalize the the inner boundaries of the polygon. Looking for a PyQGIS solution for that any other possible python solution will be fine. I tried convex hull and simplify geometry ...
1
vote
0answers
25 views

Smooth Data Values Across Geographies with Zero Population

Looking to fill in gaps through generalizing a population count across U.S. counties. I.e., if a county has 0 population, but is surrounded by 5 non-zero counties, then change the 0-population county ...
1
vote
0answers
482 views

Generalize Polygons in QGIS 3.0

I would like to use different generalization tools for polygons in QGIS 3.0. Especially for aggregation, simplifying and smoothing. Back using QGIS 2.8 there were the following possibilities: ...
1
vote
0answers
80 views

Speeding up workflow of generalizing OpenStreetMap road data?

Whenever I want to use OSM data for medium scale maps (e.g. 1:200.000) I run into problems. On the screenshot below one can see the orange street that goes from north to south. It has the attribut ...
1
vote
0answers
256 views

How to reduce the density of points based on zoom level

I have a Polyline like the one shown in the example, representing the path of a vehicle. GeoJSON markers show the vehicle's position over time. How can I reduce the density of the markers when the ...
1
vote
0answers
135 views

Line generalization not working

After having installed the plugin - Cartographic Line Generalization - I try to open the tool in the Plugins menu and receive the following error: AttributeError: 'NoneType' object has no attribute '...
1
vote
0answers
29 views

Square polygons that are covered by trees

I would like to know if there is a way to square polygons? I would like to calculate the total square meters of houses. I have extracted the buildings as well as tree coverage but I am unable to get ...
1
vote
0answers
133 views

How to generalize a raster with noisy edges with ArcGIS Desktop?

I'm trying to generalize a raster to get clean edges (see sample and "optimal" result below). However the borders bleed into each other to a rather high degree. I hacked away at the raster using ...
1
vote
0answers
212 views

QGIS: automatic generalization

I'm trying to generalize my line features with QGIS. I've tried the "Generalizer"-Plugin, but can't get the results i want. I'd like to generalize my line as shown in the image. I've tried the "...
1
vote
0answers
58 views

Condensing sparse geocodes to weighted Geo-Circles?

I have a dataset comprising 3 million records having latitude and longitude information associated with them. I want to condense it to form few thousands Geo-Circles, with radius and weight depending ...
1
vote
0answers
181 views

When digitizing Lines, vertices are automatically generalized when finished feature

I am creating lines(feature class) and when the feature is finished Arcmap 10 will automatically generalize/smoothens the line. Is there any reason why this is happening? is this a bug of ArcMap 10? ...
0
votes
0answers
74 views

Generalizing railways from OpenStreetMap using ArcGIS Desktop?

I have dataset of railways from OpenStreetMap. It is really detailed. But i want to make generalization for map scale 1:500 000: remove small details of the railways and short branches. I`ve used ...
0
votes
0answers
23 views

Reclass raster map areas smaller than specified area size

I need to reclassify raster areas smaller than 100m2 (0.01 ha) to new ones. r.reclass. area from GRASS GIS does the job for some raster sizes, but simply stucks/doesn't work on bigger ones (54000 x ...
0
votes
0answers
56 views

Simplify a polyline/polygon using a threshold on maximum number of vertices in PostGIS?

The various simplification functions in PostGIS (e.g. ST_Simplify) uses a tolerance parameter for the maximum allowable deviation of the generalized shape from the original. My question is: Is there ...