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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1answer
57 views

calculate the population inside a buffer with census data

I have population data matched with polygons and a set of points that I have drawn buffers around. Assuming that the population within each geographical area, i.e. the polygons, is evenly distributed, ...
0
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0answers
19 views

Raster to polygon with RGB composite using Arcgis

I am trying to convert an RGB composite to a shapefile to use with. The raster to polygon function returns with three shapefiles with "grid_code" of the value of each of these three channels. I am ...
0
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0answers
18 views

What replaces SQLserver SqlGeometryBuilder, for Windows store apps?

Porting Visual Studio 2008 C# application to Visual Studio 2013, Windows 8.1 store\phone app (need to include DB with the application). What DB to use (coding in c#), to replace this code, not sure ...
0
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0answers
20 views

Parcels management and land ownership

Is it possible for me to split a feature by the column area i input?Like A feature has 3000 sqm and i have in attribute table column 1= 2000sqm and column 2= 1000 sqm and based on this 2 colums to ...
1
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1answer
46 views

QGIS-->rotate polygon by a numeric value

Is there any way to rotate a polygon or a feature by entering a numeric value in QGIS thx
-1
votes
0answers
17 views

How to draw polygon next to other polygon

if I have one polygon and I want to draw another one after 3 meters with specific area , how this is possible in arcmap ?
1
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1answer
35 views

How to copy a line from polygon to an other polygon QGIS 2.6.1

I have a polygon(state) now the state divide into two. I have a new polygon with two state. I want to copy only the new border(line) which divides the two state from new polygon to old. I am ...
1
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2answers
64 views

Single polygon shapefile to multiple polygon shapefiles [duplicate]

I created a single shapefile that contains multiple polygons by selection by location of the route I had and the ESRI USA counties polygon layer to give me the counties that were in the area I was ...
5
votes
2answers
50 views

Calculating edge length of polygon within overlapping polygon

I have a layer of wetland polygons and a layer of lakes. I basically want to find the total length of lake shoreline contained within each wetland and add these values as an attribute of the wetlands. ...
1
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2answers
45 views

Multiple polygon to shapefile in XYZ format

I have an array of gridded data in XYZ format. I am trying to write shapefile (*.shp) file with multiple polygons with the pyshp python libraries. I am able to make it for only one polygon with the ...
6
votes
1answer
102 views

What do you call this non-hole edge condition?

After generalizing or simplifying polygons, you often get legitimate holes in polygons, which are separate parts and can be filled. But what is the correct term for this triangular shape? It is an ...
1
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1answer
40 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
32 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.
0
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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
vote
1answer
40 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 ...
1
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2answers
35 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
37 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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votes
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
24 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 ...
3
votes
1answer
122 views
+200

How to compute Straight Skeletons using Python?

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 ...
-1
votes
1answer
28 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
vote
1answer
40 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
votes
2answers
82 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
60 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
votes
0answers
39 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
25 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
vote
1answer
75 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
votes
0answers
20 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
vote
1answer
25 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 ...
0
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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
votes
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 ...
0
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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 ?
0
votes
1answer
45 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 ...
0
votes
0answers
28 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
vote
1answer
18 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
vote
2answers
72 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 ...
0
votes
1answer
44 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.
0
votes
2answers
72 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
434 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
vote
1answer
57 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
votes
2answers
53 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
vote
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
vote
2answers
50 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
49 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
38 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 ...