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

Split polygon into four with respect to single point

Some days ago one of my colleague came to ask me a query related to Geometries. The situation is as....There is one Polygon(suppose a city polygon) and there is one point(suppose user's current ...
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0answers
14 views

How to generate polygons upto the edge of other polygons?

I am doing some work on a pipe network (blue lines) and I am trying to attribute the information about the street to the pipes. I have 2 polygon layers one of the blocks (green hatch) and one of ...
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0answers
10 views

Split/Erase/Differentiate polygon by polygon within a same layer

Is it possible to split a polygon with a polygon within the same layer in QGIS ? As in the image, i want the Polygon 2 to be split & the pointed area has to be retained as a separate polygon. ...
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2answers
20 views

QGIS radius buffer question, can it be more circular?

Conundrum for the day, When I request a radius buffer in QGIS (Dufor). my buffer comes out as a 20-sided polygon rather than a true "circle". This has lead to some missed blocks when clipping ...
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0answers
12 views

QGIS: Clipping a line layer using a polygon and getting an empty shapefile

I am using QGIS 2.2.0 and want to clip a line layer (roads) so that only those inside a polygon are shown. When I do this using Vector->Geoprocessing Tools->Clip I only get an empty shapefile as an ...
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1answer
80 views

How to go with…somewhat complex geological maps in QGIS?

Just a follow-up to this question QGIS: Line to polygon conversion. Not sure do i have to continue there itself... We are currently digitizing a geological map...which has 36 features in total. Some ...
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1answer
38 views

QGIS: Line to polygon conversion

Currently we are working in a geological project..in which all the Contacts, Linear & some other geological features have to be captured. The thing is most of the features have to be Captured as ...
1
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1answer
30 views

Eliminate 0 Values From Raster

Arcgis 10.2 I currently have a raster file that I want to turn into a set of polygons. This will help me to create specific buffers around certain points. The extent of my values are 0, and 1. When I ...
2
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2answers
44 views

Shapely: Round Polygon Corners?

I use the python module "shapely" to make Polygons (like below). Can I convert the sharp edges of a polygon easily to round edges? Such that when I have unified some polygons I could issue a command ...
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2answers
47 views

How to select island polygons witin the same polygon layer?

i have a dataset containing many polygons. In this dataset some polygons have other polygons (as a donut) inside of them. So those island polgons are contained by only one polygon but it originated ...
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2answers
21 views

merging shapefiles . an error occured during the merge operation

i am trying to merge multiple polygons of a feature. i select them via select features by polygon and use the advanced digitalizing toolbar " merge selected features" option. it worked for some but ...
2
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1answer
25 views

Extra detailed bounding polygon from many geometric points

I have a database of around 100,000 postcodes each with lat/lon which I have converted to geom type in PostGIS. Each postcode also has one of 5 "regions". I wish to generate an accurate bounding ...
2
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2answers
140 views

Merge 30000 polygon shapefiiles in a logical manner in ArcGIS model Builder

I have 30000 shapefiles (a1.shp to a30000.shp). They are all polygons. Each polygons has one and only one polygon feature in it. I need to Merge the polygons into 1000 shapefiles. My output would be ...
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2answers
70 views

How can I group Points to make polygon via Python

I have an array of coordinates Point= [lat,long] ListPoint= [[38.203655,-76.113281],[38.10,-76.12],..] I wanna make a polygon that contains all these points ? There is a project developed by ...
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0answers
42 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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1answer
17 views

Associate points with polygon QGIS 2.2

I want to associate a point layer with a polygon layer so that I can do zonal statistics. In the image below, the polygon layer represents roughly the metro area of a certain city. The point ...
0
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2answers
37 views

How to export a shape polygon to a file

Is it possible to to export a shape polygon to a file? I want to export the polygons from a country to use them on a different map system,
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0answers
24 views

calculate distance between points crossing the antimeridian

How can I calculate the distance between two points (lon/lat) if any of the points exceeds the antimeridian (+-180 longitude)? Im using the distVincentyEllipsoid {geosphere} to calculate the shortest ...
3
votes
1answer
36 views

How to give elevation information to a polygon feature class using existing TIN file ? (geological mapping)

I'm an ArcGIS 10.1 user. My issue: I have a printed form of a map which depicts geological bodies being surface rock occurence. Additionaly, there are elevation contour lines. I digitized the map by ...
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1answer
58 views

How to obtain the maximum/minimum longitude and latitude for a polygon?

I have the MSA/CMSA shape file which contains 274 metropolitan areas. How do I have to obtain the maximum/minimum longitude and latitude for an area? So, it's like drawing a box right outside and ...
1
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0answers
21 views

Entity handle from Visio

I have successfully imported the polygons from a Visio diagram via dxf into QGIS by using the "space" shape in Visio (a normal rectangular shape comes through as polylines, not as a polygon). Very ...
2
votes
1answer
41 views

Compute the area of a given polygon (in vector format) lying between specified lines of latitude

I have species distributions (in vector format) and I would like to calculate how much of the area for a given species distribution is within certain lines of latitude, such as temperate and tropic ...
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2answers
53 views

adjusting polygons to boundary and filling holes

here's the problem: Where: 1: department boundary 3: polygons inside department boundary that "touch" the department boundary(1). They are not necesary fitting well inside 2: holes between 1 and ...
1
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1answer
30 views

Calculating distance between borders when one polygon inside another polygon?

I am brand new to ArcGIS and having some trouble. I would like to calculate the distances between the border of one polygon to another polygon. However, these polygons overlap. Thus when I use the ...
4
votes
2answers
87 views

Converting shapefile to raster: Character attributes

I've got a shapefile that I would like to convert into a raster, but the trick is that the attribute I want a raster version of is character data. I'm familiar with geoprocessing using GDAL (in the ...
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2answers
39 views

How to select and shade polygons I am interested based on existing shape file in Arcgis 10.2

The shape file already includes polygons I am interested and others. I want to make a map put in my paper showing which regions in the world I am interested. Thanks.
2
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1answer
24 views

How to dissolve geodatabase map across two subdivision levels in Arcgis 10.2

The existing polygon database contains attribute table with the following structure, and has three levels; country, state, and city (and many other countries not listed below). I want to dissolve the ...
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0answers
39 views

How to generate random GeoJSON polygons (latitude, longitude)

I am looking how to generate polygons in GeoJSON format with random locations (latitude, longitude), if I generate totally random set of points it will not produce valid polygons. So my question is ...
4
votes
3answers
97 views

How to shrink polygon on two sides?

I have a polygon which I know is a rectangle, although it may be at any orientation: I want to shrink this polygon by a third of the width from two sides, so that I just get the strip in the middle ...
0
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1answer
17 views

CartoDB simple process

I'm attempting to create a simple process with CartoDB, I have a layer with number of polygons, I want to to run a SQL with a multipoint line to report which polygons were intersected.
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1answer
47 views

Looking for a simple hatching algorithm

If I have an arbitrary polygon, and wish to hatch it with lines at a given angle and spacing, is there a simple low-level algorithm which will return the set of hatch lines inside the polygon?
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2answers
60 views

Simplify Multigeometry polygons in QGIS

I am really new to QGIS and KML so this might be obvious but I am too ignorant to know what to do. I have some KML files I would like to use in an application but they are much more complicated than ...
2
votes
2answers
99 views

How to convert a shapefile to a grid file

I was wondering whether anyone might be able to tell me in layman's terms how to convert a polygon layer to a Grid file in ArcGIS 10.1 or ArcGIS 10.2?
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0answers
17 views

save polygon from image to PostGIS database

I'm working on a software to detect buildings from satellite imagery. so far I have managed to separate the building with other objects of the image. My problem now is how to save every building in ...
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0answers
20 views

QGis Filtering postgis layer with boundbox

I know It is possible to split a polygon feature by interactively drawing a line over it in QGIS 2.0 with the Split Feature command.The issue i have is that postgis layer i am trying to work on is ...
3
votes
1answer
55 views

PostGIS - when I add a polygon, delete overlapping areas in other layers

I'm starting to work with PostGIS and I'd like to solve the following problem: In my database, I have multiple land use class layers, for example: "residential", "industrial", "commercial". The ...
1
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0answers
34 views

Why does it take so long to run zonal statistics?

QGIS 2.0 Windows 7 I have pulled agricultural data from NASS CDL in tiff format. I want to track where a certain crop has grown over the years. My intention was to use a county shapefile overlaid ...
2
votes
1answer
47 views

Area of polygon split by a line

I need a query that return the area of two polygons that have been split by a line. This is what I did so far: SELECT ST_Area(ST_Split(surface.geom, limite_a.geom)) from surface, limite_a where ...
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0answers
21 views

Splitting polygon layer and joining attributes

I have two shape layers -- one a layer of counties in Florida and another a layer of MSAs in Florida. I would like to generate a new layer that has the following properties: MSAs that overlap more ...
0
votes
1answer
37 views

Numbering rows and columns in polygon grid (fishnet)

I seem to be a bit stuck on what i thought would be quite straightforward. I've created a fishnet of polygons, all 25 x 25 metres, 100 polygons by 100 polygons. My main task is to create a ...
2
votes
1answer
61 views

How can I filling ring in QGIS 2.2?

I created a polygon which covers a park. But I want to distinguish some small buildings located inside the park. Consequently, I want to distinguish them and use them as independent patches inside the ...
2
votes
1answer
34 views

Calculate the number of points in a freehand polygon ArcGis Javascript API

I'm drawing a free hand polygon on my map. Now I want to calculate the number of points found in that polygon. I have done this code, which my now is giving me the number of points found in the map ...
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3answers
102 views

How combine different geometry types into the same feature class

I've searched the question in this blog. Maybe I don't use the right words but anyway my problem is not present in any post so I'll try to explain my question by opening a new one. I have a polygon ...
1
vote
1answer
56 views

How do I add coordinates to a polygon layer to be able to sort the polygons from north to south in QGIS?

I have a polygon file, where each polygon represents one property. I want to be able to sort the polygons from north to south or vice versa. I need them to be sorted in this way when I export them to ...
2
votes
1answer
57 views

Batch create fishnet using FME

I want to create a fishnet based on the extent of individual polygons from a list of polygons. I plan on processing each resulting fishnets further. I am maintaining a worldwide data set on Quarter ...
1
vote
2answers
79 views

QGIS Valmiera, Labels only show for part of polygons

Using 2.2.0-Valmiera on Ubuntu 13.10 I have for Croatia 21 Counties as polygons. Labels show only for 12 counties: here I see that no labels are shown for multipart features. So I checked "Show ...
0
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1answer
32 views

Get all points with in some range of a point (or range of point)

I have got a list of points and a fixed range (10m). So what I have to do is for each point I have to find all the points present in a table with the 10m range of the given point. For example: Let ...
0
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0answers
15 views

GRASS GIS - v.select- ERROR: bad allocation -

I'm quite new to Grass GIS. I have two vector maps, one of a grid (each grid cell is a polygon) and one of a much larger polygon. I've been trying to select the grid cells that lie completely within ...
3
votes
1answer
53 views

T-shaped polygons

Is there any coefficient that can indicate T-shaped polygons ? Examples of T-shaped polygons :
1
vote
1answer
45 views

Identify geographic location to points

I am quite new in QGIS and I really need your help. I have a map of Kenya divided into 68 districts and I have coordinates of 30.000 schools. The points have one variable besides the latitude and ...