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
24 views

How to Convert db.ListProperty(GeoPt) to GeoJSON Polygon

My Python Google App Engine (no tag?) app has a datastore model of an Area of Interest, simplified as import geojson class AreaOfInterest(db.Model): name = db.StringProperty(required=True) ...
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0answers
51 views

Visualizing overlapping polygons by occurence

I work in a library providing geospatial services and I have a patron with about 60 surveys with perceived accent regions in Mexico. Individuals drew on maps where they think people speak with ...
1
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1answer
121 views

Extract data from netcdf using a shapefile polygon in python

I need to subset data from a NetCDF using a specific shapefile. The data are sea surface temperature and ocean color at 1/4 degree resolution. I have 4 polygons describing the US. Northeast ...
1
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1answer
137 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 ...
3
votes
1answer
75 views

Using arcpy to find geometry within another feature

In Arcpy, I would like to start with a point and then using its geometry method to find out if it is inside my polygon feature (Urban Areas) deeper than the buffer distance. This is a follow up to ...
0
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0answers
17 views

Losing polygons when importing shapefile in GRASS

I have a complicated mapinfo .tab file of wildland urban interface zones. They are represented as polygons. I am importing into GRASS using the following command: v.in.ogr -c dsn="C:....path" ...
1
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0answers
51 views

Convert polygon to raster and give value to null cells

Is there a way to convert polygon features to raster while also populating null cells with a specific value? As in, can I create a raster from a polygon shapefile and have the tool populate all null ...
1
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1answer
38 views

Using pyQGIS transform a layer of polygons into a layer of holes inside a bbox

I'm using python in QGIS. I have a layer of polygons (its a result of some earlier dissolving and has no overlapping polygons but some holes and islands in holes etc). I want to build a new layer ...
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0answers
48 views

QGIS - Polygon to Lines Tool Incredibly Slow

I am trying to convert a few polygons to polylines so I can save them as a .GPX file. I'm using QGIS 2.8.1 (Wein) on the Mac. It seems to be hanging. I only have a few small polygons (see ...
1
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2answers
30 views

add polygon to layer from text file [closed]

I am completely new to Qgis and to gis in general. I have start to work my way through the documentation but have a question that I can not find a answer to. When looking into the documentation ...
0
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1answer
27 views

TopologyException error during fortify SpatialPolygonsDataFrame

I tried to reproduce a recent question on spatial data visualization using ggplot2 and received the following error message during fortify(world, region = "ISO3"): Error: TopologyException: Input ...
1
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0answers
35 views

Correcting polygon geometry so edges can be reshaped to match that of subsequent layer in ArcGIS for Desktop?

I have two layers; a polygon layer representing maritime boundaries/economic areas of countries in the world and another polygon layer representing all countries but with a detailed coastline. In the ...
3
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3answers
246 views

Is there Shape Metrics Toolbox or equivalent for ArcGIS 10?

I need to compute the geometric properties (e.g. contiguity index, dispersion index etc.) of a series of polygons and I would like to use the Shape Metrics Toolbox. I am using ArcGis 10 and the ...
2
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1answer
76 views

Feature is a point or polygon

Im new to GIS and am just curious if there is an instance where a feature can be a point in one map and a polygon in another map and vice versa?
0
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0answers
49 views

How to properly import georeferenced .dxf hatches/polygons into QGIS?

I have a georeferenced AutoCAD-drawing (some district borders I vectorized with Illustrator from a raster image), saved as a 2004 ASCII .dxf-file. When I import the file in QGIS ("Add Vector Layer"), ...
5
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3answers
10k views

How to Merge/Dissolve Polygons By Common Attribute Field in QGIS?

I have joined corresponding Local Enterprise Partnerships table data into a polygon shape file containing UK Local Authorities. How do I Dissolve or Merge the the Local Authorities polygons by ...
0
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4answers
168 views

Fix Self Intersecting Polygons Manually

I are looking to implement a method to fix self-intersecting polygons by editing the vertex order. We want to take the polygon rings and re-arrange/add in vertices to make a valid polygon. This is ...
5
votes
3answers
9k views

Converting multiple lines into single line using ArcGIS Desktop?

I've no idea if this is basic or what but I have this data that contains multiple lines (forming a polygon shape). I want to convert those lines (multiple - each with a start and end point) to a ...
0
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2answers
44 views

How can I find internal overlaps in my polygon feature class ideally via modelbuilder tools?

I have a polygon layer containing "depth curves" for the making of a skin of earth kind of map. I want to check whether or not my feature class contain any overlaps internally between these polygons. ...
3
votes
2answers
123 views

Creating polygons from line segments using PostgreSQL and PostGIS

Is there a PostGIS function that creates polygons from multiple line segments? I want to convert the pictured thirteen lines to four polygons. All lines belong to the table "boundary" (gid, geom). ...
1
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0answers
30 views

Progress Bar gets stuck converting Lines to Polygons using QGIS?

I'm trying to convert lines to polygon using QGIS 2.8.1. I use Vector > Geometry Tools > Polygons to Lines. I always get the progress bar stuck on 90%, it can't get to 100%. Could someone ...
1
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0answers
45 views

Matching (joining) two slightly incompatible polygon shapefiles

I have two shapefiles that represent two slightly different zonings of the same area (municipality zoning and transport zones), about 3000 polygons each. Several smaller municipalities may form a ...
5
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2answers
3k views

Removing sliver polygons in ArcGIS Desktop?

I unioned 2 layers into 1 layer, and it created sliver polygons. I used the elimination tool to merge them with neighboring polygons. As as result, it merges all sliver polygons to only one polygon ...
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7answers
24k views

Removing small spaces (slivers) between polygons?

I have a set of polygons representing administrative districts. The districts were digitized by hand, and there are small spaces (slivers) between polygons where the polygons should be touching. How ...
0
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0answers
57 views

Grouping Analysis (Clustering) of polygons with streets as borders in ArcGIS?

I have a question about the Grouping Analysis Tool in ArcGIS. Is it possible to use streets as spatial borders for the groups? I want to group a city district autmatically with multiple attributes, ...
2
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0answers
89 views

Different obs. when I extract raster values from polygons in R

I have two raster layers with the same projection, extent and resolution: r1: class : RasterLayer dimensions : 33434, 89431, 2990036054 (nrow, ncol, ncell) resolution : 0.001447053, ...
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0answers
10 views

How do you snap polygons as you draw in QGIS? [duplicate]

I need to draw a long row of patient rooms for a hospital. I have the following plugins installed in QGIS 2.6: Rectangle Ovals Digitizing CAD Digitize I want to drag a set of polygons that aligns ...
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0answers
35 views

Sample points based on underlying polygon attributes

I have a point shapefile and I would like to sample those points (just like the "Sample" tool allows points to sample underlying raster) to receive a table with underlying polygon values (interested ...
1
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2answers
100 views

Is there any library can perform polygons buffering/ inflating/ merge/ overlap at server side?

I have a set of polygon data express in lat long. I would like to perform some tasks (polygon buffering, inflating etc etc ..) in server side and output the result to client side (client is a web ...
0
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0answers
24 views

Selecting polygons using another polygon? [duplicate]

Hi, How is the best way or fastest(if there is) of selecting polygons of a different shapefile using a polygon of another shapefile. exercise example: i want select all the light brown polygons ...
1
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0answers
52 views

Why does the transformation bring bad results?

I have this map which has a polygon drawn on it. For the background map I use a WMS via ol.source.TileWMS and the polygon uses a ol.source.Vector object. Normally my view projection is EPSG:31467 but ...
0
votes
1answer
286 views

How to create polygon feature class from UTM coordinates?

I am working to create a polygon from UTM coordinates. The script I am using fails with a "must be a sequence, not float" error: Traceback (most recent call last): File "F:/sample/clipTiles.py", ...
0
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1answer
33 views

Python error in polygon to raster conversion

I want to convert polygon to raster. I converted the dbf file ( "cntymam") to table view to make use in the conversion. I am getting a error that the parameters are not called and also with the grid ...
1
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1answer
67 views

Select points near polygon in Postgis

I'm trying to make a spatial query, but I think something is wrong with it: I have two tables, places (point) and cities (polygon) When I try to get the points within 500m to one point, there is no ...
2
votes
0answers
37 views

Redistribution of polygons: supplementing and filling the specific area with polygons with specific size

I'm studying the impact of green wedges (red outline on the figure) on weather parameters in Copenhagen area. What I want to do is check how spatial redistribution of future afforested areas enacted ...
1
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1answer
140 views

draw square openlayers 3

I am starting to convert old code of openlayers 2 to openlayer 3. In the old version you could make polygon shape based of the amount of sides like in the example below: ...
1
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1answer
53 views

Parts of geometry disappearing in QGIS export to Illustrator PDF

I'm having this issue with certain polygons when I export to PDF. Everything looks fine in QGIS, everything fine in print composer, everything fine in the PDF as viewed in Preview or Adobe Reader. ...
0
votes
1answer
102 views

How to scrape polygon data from web map?

for each value of parcel no: in http://www.ma-investment.gov.bh/bps_ppd_en/ the map generates polygons. I want to extract xy values corresponding to polygon shapes which i can convert to ...
1
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0answers
151 views

Geofencing: Query if a POINT is within a POLYGON

I am trying to use the following query to search if a point is within a defined POLYGON (aka a geofence I want to define): ...
0
votes
1answer
162 views

Intersecting Overlapping Polygons Individually in ArcGIS

Map Layers: -Census Tract Shape File w/Population Data -Set of Store Locations with 5 Mile Buffers (Significant Overlap Between Buffers) I have create feature layers for both and I am trying to ...
2
votes
2answers
1k views

Zonal Statistics as table creates output but some are Null

I have temperature as a raster file and different ecoregions of a province as polygons. What I want to do is calculate the mean temperature per ecoregion. I succeeded in doing this by Zonal ...
1
vote
1answer
40 views

Adjacency matrix from polygons in GeoJSON

I have a set of polygon features in a GeoJSON file. They are neigbourhoods in Chicago. I would like to produce an adjacency matrix A, in CSV format or any other form, where the i,j element of A is 1 ...
0
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3answers
62 views

Counting number of Raster Cells satisfying a criteria within a Polygon

I have a USA raster dataset, which assigns to each cell a value from 0-100. I also happen to have a USA county shapefile. I simply want a count of the number of pixels/cells in the raster data with ...
8
votes
5answers
5k views

How to remove only donut holes from polygons using ArcGIS Desktop?

I am using ArcGIS Desktop 10.0. I have a trick for removing the donut holes, which is converting the polygon to line and then creating polygon out of the lines and in the end merging all of them. ...
0
votes
1answer
25 views

Assigning values from one polygon to second polygon if located within first using ArcGIS for Desktop?

I have two layers of polygons. I would like to know if there is a way to assign a value from a polygon in the first layer to any polygons from the second layer that fall within that polygon?
0
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1answer
54 views

Measuring areas in WGS 84 [duplicate]

I started a QGis project with adding information layers from OpenStreetMap such as the streets and railways for a city. This data has WGS 84 CRS. After that, I made a shapefile with urbanized bodies ...
0
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0answers
40 views

Transforming GIS based XY data (polygons) so that they overlap in R

So I'm attempting to come up with the average shape of these polygon features as a part of my masters research. To do this, I want to run a shape analysis of GIS-based X-Y data using the shapes ...
0
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0answers
47 views

Clip Image by polygon and create memory raster

I need to write a code in c++ that can clip an image (4 bands) by using individual polygons in a shape file. I need to access the values of pixels (from all 4 bands) are clipped by a polygon. I do not ...
6
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2answers
2k views

Easily calculate “roundness/compactness” of a polygon

I am trying to find ways to quantitatively describe the shapes of various polygons. For my project, these polygons represent lakes, rivers, lagoons, and parks. So they can be almost any shape. One ...
0
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0answers
81 views

Change SHP Projection to display on Google Map

I'm pretty new to GIS but not to programming, so sorry if this was already asked. I didn't find a solution not sure if I didn't quite understand everything about Projections and so on. I have a GIS ...