On a map, a closed shape defined by a connected sequence of x,y coordinate pairs, where the first and last coordinate pair are the same and all other pairs are unique.

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20 views

Why is my map zoomed in so ragged compared to what I actually drawed in QGIS

So overall my map looks the same like what I draw in QGIS. The issue is that when I zoom in, in that case 54x then you can see ragged lines. QGIS Browser That is not what I need. I need high ...
1
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2answers
28 views

How to get the number of polygons of a geometry in PostgreSQL

How can I get the number of polygons that form a geometry in PostgreSQL? For example U.S map has a lot of islands in addition to its main lands. I want to count these islands plus the main lands.
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0answers
23 views

How can I redistribute points within a polygon using certain criteria in ArcGIS?

I have some points (representing pharmacies) scattered around my research area and I would like to redistribute those points through the area using the following criteria: The points should ...
1
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1answer
32 views

How to create Spatial Reference System in QGIS?

I have some Attribute and the coordinate and the coordinate reference system. I want to create a DBmanagamet form my spatial data. To do that I want to create one table with name Spa_ref_sys, but I ...
1
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0answers
18 views

QGIS - Label polygon with different projections

I have a polygon layer projected in an UTM. In properties I checked 'show all labels for this layer'. Does anyone know why the label does not show until zoom 15:1 in QGIS with CRS-4326, while in ...
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2answers
33 views

Using GDAL to get vertices of a multipolygon

I am successfully using GDAL to get the vertices of a polygon from a ShapeFile using .NET code. This link showed me how to do that: ...
0
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0answers
31 views

Polygon of Voronoi cell using scipy.spatial?

I have points (e.g., lat, lon pairs of cell tower locations) and I need to get the polygon of the Voronoi cells they form. from scipy.spatial import Voronoi tower = [[ 24.686 , 46.7081], [ ...
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0answers
47 views

How to find a point inside a multipolygon?

I have a table postGIS with a column (type: geometry(Multipolygon)). One of the entries looks like below. How do I convert them into polygons ? or If I have a geo-coordinate , is there a way to find ...
1
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0answers
21 views

Inflating the boundaries created with convex hull

I have a set of lan and lat points and have plotterd a convex hull for them using QGIS. A polygon is created along the set of points and plotting them on the MAP. Now I am trying to inflate the size ...
1
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1answer
59 views

Is there a Python implementation of a Straight Skeleton algorithm?

I'm looking for a Python package which provides an implementation of a Straight Skeleton algorithm. I'm aware that the open source (C++) project CGALcontains an implementation but it seems like ...
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1answer
24 views

Partitioning Polygons layer to smaller partitions

I Have a huge polygon layer which contains many thousand polygons> i am going to operate an intersect loop for every point in the layer with near polygons. i use ITopologicalOperator op = ...
1
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1answer
37 views

Split polygon into several smaller polygons in QGIS

I have a layer of polygons depicting response boundaries, I would like to break each of these polygons into a number of sub-polygons. As this is for an exploratory project, the polygons themselves ...
2
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2answers
81 views

ArcGIS lines to polygons without holes

I have a dataset with contours. Depression contours are separate of the normal contours and need to be digitized counter-clockwise. Still, there are usually some faulty ones with wrong direction and ...
0
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0answers
57 views

Polygon vertex “duplication” in QGIS?

New QGIS user, Brighton 2.5. When creating or moving new vertex points of a recently-cut polygon (hence adjacent polygons) I get "duplicate" or "criss-crossed" lines beneath the former vertex ...
2
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0answers
37 views

Polygon Layer Cleaning with QGIS

I have a little situation with my data. I have vectorized a raster layer, and now I have some issues with the geometries, as you can see in the picture. Most of errors I have are like this one. ...
1
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0answers
21 views

merge polygons of single feature QGIS

I am new to QGIS and have done some research on this topic before posting but not sure I found an answer. I have one feature that has multiple polygons (islands of a nation). In reality, there is ...
1
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1answer
69 views

postgis: cluster/group points based on distance

We have a set of thousands of points and want to group all of those which are within 100m distance from each other (to get the centroid from each group). A first idea was to build 100m buffers around ...
0
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0answers
19 views

ClipRaster Class of DotSpatial is problematic

I want to clip a raster data with a polygon extent. Here is my Layers. Polygon layer is colored and raster is black and white. When I cliped using ...
1
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1answer
24 views

Edit existing Polygons to include several new nodes

I want to define catchments which are quite large from vector contour data. I normally start zoomed out to define the catchment generally as it is easier to see. I then zoom in and refine the ...
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0answers
19 views

Stack profile - polyline length

I have created a polyline that stretches from one side of a beach to the other (vertically). I have lidar data for 2005 and 2013. I am trying to compare the changes in morphology of the beach from ...
0
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1answer
31 views

Create polygons from point dataset, where each polygon contains 3 points from the dataset

I'm using qgis Brighton I have a dataset of 1500 points. I want to create polygons, where each polygon contains n=3 points from the dataset. The aim of this is to have clusters of 3 points, which ...
1
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0answers
42 views

Is it better to work with non-contiguous or contiguous polygons?

I would like to find width-height of a non-contiguous polygon in order to draw paths within it. My question: Is it better to use a bounding box (contiguous polygon) and then clip keeping my real area ...
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0answers
20 views

Drawing polygon with predetermined area

Is there an option in quantum gis to draw a polygon with the specyfied area and is it possible to display dynamically the area when reshaping the shape of the polygon ?
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1answer
44 views

How to avoid 'join features by location' for polygon to polygon creating extra areas

I am trying to work out which large polygons contain smaller ones within them in QGIS. I have a set of smaller features already defined (dark green below). However, for those smaller areas which sit ...
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0answers
25 views

Zipcode to Polygon/Boundry

Is there any API out there which can give me Polygon value for a zipcode? I really thought that it would be fairly easy for me given the number of Maps APIs out there. Either Google Maps API or ...
1
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1answer
17 views

Is there any way to know if a polygon is part of another bigger polygon(s) in SQL server?

Basicaly, what I am trying to do is we have a lot of geographical containers like territories, sub-territories etc. and the boundaries of each keep on changing all the times and I have to store the ...
1
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2answers
71 views

Intersection point of polygon and the line created by two points ArcPy

I have polygon layer. I selected the most distant vertex from centroid (picture: point A). (How to do that is in the answer here: Select the most distant vertex from polygon's centroid using ...
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1answer
39 views

How to export to all points within Leaflet polygon?

I dont have any idea If it is possible to export all points within a draw polygon. (http://leaflet.github.io/Leaflet.draw/). Thanks in advance.
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2answers
69 views

How do I json_encode without those quotes for the coordinates in leaflet geojson polygon?

I have a field name: 'coordinates' I have the coordinates stored in there: like this: [[ [100.0, 0.0], [101.0, 0.0], [101.0, 1.0], [100.0, 1.0], [100.0, 0.0] ]] when I json_encode($geojson); I get ...
4
votes
3answers
427 views

How to subtract polygons from polygon?

I have two polygon layers, one is green that represents all non-public right-of-way land. I have another polygon that is just a circle with a specified radius. I would like my output to be a polygon ...
1
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1answer
54 views

Overlapping polygons in the same layer

I am working in QGIS on a vector layer where areas are classified using an attribute "typo". The problem I'm encountering is that many polygons are duplicated or overlapping, with the result that some ...
4
votes
3answers
113 views

Select the most distant vertex from polygon's centroid using ArcPy

I have a poligon and the polygon's centroid. I want to select the most distant vertex from centroid (picture: point A). I used arcpy.FeatureVerticesToPoints_management to create a feature class ...
0
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2answers
48 views

Intersection between line and polygon

I have 2 layers in openlayers: first is parcel layer (polygons) and second is railway layer (lines). They are already drawn and all i need to do is when i click on some line, to get intersection of ...
1
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0answers
30 views

Calculate Sum on One Field Within Several Different Point Feature Classes?

I have several point feature classes (eg: the location of mall, liquor stores, etc), that I need to get the count of within a specified city district. Basically, I want to great a modelbuilder model ...
2
votes
1answer
92 views

Is there a way to give the drawing red polygon a higher alpha channel

Is it possible to set the alpha channel a bit higher when drawing? I don't mean the alphachannel of a already finished polygon, that's possible for sure! I mean the red area. It's really stressful ...
1
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2answers
44 views

How to separate polygons within layer and measure line through each polygon?

I have 3 layers of polygons, each layer with multiple polygons spatially separated, although the layer only counts it as 1 polygon. I have a layer with a line going through these polygons. What is ...
4
votes
2answers
68 views

Why does qgis give multiple centroids per polygon?

I have a shapefile for the boundaries of European NUTS regions, and I would like to compute the centroid for each of those regions. When I do this in QGIS (2.6.1 on OSX, using polygon centroids from ...
2
votes
1answer
43 views

Simplify a polygon dataset with a minimum distance between the new vertices

I would like to simplify a polygon shapefile where the resulting output has a minimum distance of 5 kilometres between the new vertices. We have ArcMap 10 on an ArcView license, FME and QGIS. I have ...
0
votes
1answer
36 views

Merge two points of two different polygons to get one polygon at the end

I would like to join points from two different features. I already searched for plugins but so far but didn't find one working plugin or solution for my task. So here is a picture of 2 ...
0
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0answers
31 views

line features show up as polygons in GeoServer

the layers are located in a postgreSQL Enterprise Geodatabase. I created a new line feature class and added it to the database and then added it to geoserver. But in geoserver it comes in as a polygon ...
2
votes
1answer
37 views

Is there a way to disable right-click in QGIS when drawing

I would like to know if I can disable the rightclick in QGIS. The issue is that I draw polygons that are kind of big, let's say 4000 polygon points. And as you know rightclick brakes the drawing ...
1
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0answers
28 views

Merge zip code based polygons to create sales territories

I have access the full data set of the KML file shown here: http://www.maptechnica.com/downloads/samples/mt_2014a_kml_us_zcta5_sample.tar.gz Here's what it basically looks like: ...
0
votes
1answer
49 views

Converting polyline data to polygons?

I am trying to convert some polyline coastline data into a polygon that I can use to clip/subset back other data sets by this polygon. There are some small gaps in the coastline data, which ...
0
votes
0answers
36 views

Is it possible to calculate area of polygons from GPS points without POSTGIS

I am new with GIS. Assume we use the UTM30N coordinate system. Is it possible to calculate an area (say a square box) by the 4 given points? (assume the points are in order, and the coordinates are ...
4
votes
2answers
61 views

POSTGIS get the max length of the polygon and the average width

I have in postgis a polygon type table. I need to calculate automatically the maximum length of the polygon: And the second one is the average width: I am doubting rigth now if this is possible ...
3
votes
4answers
124 views

Is there a way of auto_increment for the ID column in QGIS

I'm creating a fictive map and so I need to create lots of points, lines and for sure polygons. Later on I export my data as geojson. But before that I aways have to go and give every element an ...
2
votes
2answers
176 views

How to count point shp inside polygon shp using Python?

This is my first time here, so I'll try to be as specific as I can. What I'm trying to do is found out which polygon contains the most points and write the result in a text file. Here is my script : ...
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0answers
18 views

Select a polygon which is just partly member of another polygon with its area of the other polygon

I need to generate random points within geometries, which works quite good, but there are some small errors. Take the picture below. There are some greenish and redish Polygons(?!) which do not have ...
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0answers
14 views

combine multiple geojsons

I have several geojsons which contain polygons. But the polygons are reaching over other geojsons. When I import them into lets say Qgis, the polygons, which are distributed among several geojsons are ...
2
votes
2answers
55 views

OGR DXF Closed Polyline Conversion

I'm trying to convert closed polylines into polygons using ogr2ogr from dxf to mssql. Here It says that polylines are converted into POLYGON if they are closed, but I always get the type LINESTRING ...