Process of creating geometric polygon features.

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2
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2answers
71 views

Can't transform lines to polygons

I have a similar question to: How to join lines in QGIS for later using "lines to poly"? I have a line shapefile that I wish to transform into a polygon shapefile. After making some ...
2
votes
0answers
66 views

How to extract polygons from a road network?

I need to extract faces (or polygons) from my road network and calculate their areas. I mainly use Arcpy packages but even if you know it in QGIS APIs, I'd appreciate if you'd share it with me. If it ...
2
votes
1answer
103 views

Polygon Between Contour Line

I have a contour generated from SRTM, How to fill the space between that contour with polygon (for all part) but it generates field in attribute table automaticaly, example in image above between ...
1
vote
2answers
65 views

Creating counties in QGIS

I have a raster map (a photocopy I took from an Atlas), and a vector map of the UK. The raster map shows pre-1890 Scottish county borders. I have geocoded the map so that the raster borders overlap ...
2
votes
2answers
324 views

ArcGIS: Create polygon using file containing point coordinates

I have a text file containing the projected coordinates of the points that define a single polygon. The X, Y coordinates are separated by Tab Is there a tool in ArcGIS similar to "Add X,Y Data" in ...
1
vote
3answers
72 views

How can I insert a bounding box or polygon in a PostGIS geometry field?

I have a field in my table called 'geometry' that was created thus: CREATE TABLE "public"."sites" ( "id" int8 DEFAULT nextval('sites_id_seq' :: regclass) NOT NULL, #... A few MORE fields ...
2
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0answers
60 views

Weird-looking France after OSM import with osm2pgsql

After importing france-latest.osm from Geofabrik, using osm2pgsql, it seems that the polygon attributed to Metropolitan France (osm_id = 1403916) is a bit odd: I'm far to be a geography expert, but ...
1
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1answer
61 views

Dynamically drawing a polygon around another shapefile, ArcGIS 10.2

Let's say I have a vegetation raster that indicates the density of forest all over the world. I also have a shapefile that contains the admin boundaries of each country in the world. The easy part is ...
1
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1answer
41 views

Raster domain output polygon has is an empty feature class. Shape_Length and Shape_Area = 0

I am trying to convert a 32-bit floating point raster with 205289 columns and 120615 rows to a polygon using Raster Domain. It creates a feature class that does not contain any polygon. There is a ...
1
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1answer
32 views

Creating contiguous / adjacent ellipses

I've only just started using drawing tools in ArcGIS, and have the following question I haven't found the answer to online. Is there a way of taking a drawn ellipse (at a slight angle) and adding say ...
0
votes
1answer
42 views

Adding custom shapes to a new shapefile

I am using ArcGIS 10.1 and I drew a rectangular shape to designate a junction on a map and i would like to add that to a new shapefile. Could you please give me some ideas.
1
vote
1answer
76 views

Distance analysis of 3-D surface in ArcGIS using VB.NET

Using VB.NET I created a 3D polygon in ArcGIS to model a fault plane and now I want to find two different distances from a point on earth's surface. How to go about this? Can some one help with the ...
0
votes
1answer
50 views

Difference between 'point' and 'WKSpoint' in ArcGIS

I have to add 3-D points to make a polygon in ArcGIS using VB.NET. I have defined an IpointCollection and want to add points to this. I have options to add 'point' or 'pointcollection' or 'WKSpointz'. ...
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0answers
40 views

“Flood fill” polygon capture mechanisms in various GIS

Within our organisation we have a requirement to capture lines dividing land into chunks and then to create polygon features using aggregates of these divisions. In the example image below ...
7
votes
2answers
317 views

How to extract vectors from map using QGIS?

I am trying to extract building footprints from a raster map (as shown in the example below). Please note that the maps are out of copyright, have been scanned and georectified by a library and have ...
0
votes
2answers
92 views

I have a table with a series of lat/long points - how do I convert them into polygons?

I have an Excel sheet with about 150 points (lat and long in decimal degrees) which belong to about 15 different polygons. The columns I have are FID, NAME (the same between polygons), POINTS (points ...
1
vote
1answer
558 views

How to create a polygon feature class from polylines in Python Arcgis?

I am trying to create a polygon from polylines. I've created this script but it gives errors of Arrays. Thanks. import arcpy polyline=r'C:\temp\temp_lines.shp' ...
0
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2answers
163 views

creating isochrones in postgis/osm2po/pgrouting and then saving the isochrones as polygons

So I am creating some isochrones in pgrouting based upon a table from osm2po. Now I have a query that will get all of the edges that are c driving distance away from a point. My question is, how can I ...
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0answers
14 views

creating Polygon from LineString and a width

I have to create a Polygon from a lineString and a width. Ex: Given a street as a lineString (Or a list of points) and a width, create the polygon (the road). I am using Geotools, but I couldn't find ...
0
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2answers
167 views

How to create polygons from unclosed polylines?

I have a layer of driveway that is in polylines unclosed . They are just two parallel lines outlining the width of the driveway. Then again, there is a gap (sidewalk layer) and driveway continues ...
2
votes
1answer
177 views

Convert SpatialGridDataFrame in to polygon shapefile in R

I have a SpatialGridDataFrame in R and want to plot just one of its attributes as as polygons in a GIS. There seems to be no simple way to do this. The situation is complicated by the fact that the ...
0
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2answers
94 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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2answers
178 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 ...
0
votes
1answer
165 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 ...
1
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1answer
198 views

Python: Ray-trace a WGS84 point with heading and distance

One of my services defines geofences for a mobile app. The geofences consists of a lat/lon pair and radius in meters, in JSON, e.g.: { "geofenceId":"geofence_b39da38cff7be4b4693cbc31b2394bbb", ...
1
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1answer
127 views

How to create polygons from a polyline graticule?

I'd like to make a polygon shapefile out of a polyline shapefile showing a graticule. However, using the "Line to Polygon" tool results in a peculiar...something: Other standard tools like ...
1
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1answer
43 views

How to edit line and polygon layers at the same time?

I have two layers, lines and polygons. Lines are basically the boundaries of the polygons. Is there any way that when I change or reshape the lines the polygons get updated automatically? I normally ...
5
votes
1answer
158 views

How to grow several concave hulls until they completely fill a larger area without overlap?

This is my problem: I have a very large point layer with polling station locations across one country; each point belongs to a specific constituency (900k points, 4k constituencies). I wish to use ...
0
votes
1answer
70 views

How to copy closed loop lines into polygon feature class

I'm trying to utilize line contour data to find the volumes of local depressions. To do this, I want to copy the closed loops formed by depression contours into a polygon feature class to find the ...
0
votes
1answer
53 views

How to generate evenly sized polygons within a boundary

I have an area and need to create evenly sized polygons within the area. It doesn't matter where the polygons fall, only that they don't overlap and each area is the same. They needn't be ...
4
votes
2answers
58 views

How do I create blocks from a road network?

I have a road network and for every enclosed area within the network I want to create a polygon that represents that area. How does one do this?
2
votes
2answers
241 views

Shapely MultiPolygon Construction - Will not accept the entire set of Polygons

I am new to Shapely, so I am using a work request to learn a bit more about it. I need to execute a number of unions to build larger geometries from assessment neighborhoods in DC. I am curious ...
1
vote
2answers
222 views

How do I create a polygon layer from multiple touching line segments in QGIS?

I'm trying to create a base map for a Maine Coastal area, and wanted to create a polygon layer of the land cover from the coastline in QGIS. Whether I created the coastline vector layer from the USGS ...
0
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0answers
84 views

How do I optimize the speed and enable ArcGIS to create the Service Area around my locations?

The Problem: Every time I try to solve the service area around locations, ArcGIS crashes. It takes forever to load facilities and draw just a single polygon. How do I optimize the speed and enable ...
3
votes
0answers
173 views

Postgis - extrude a polygon

I want to extrude a polygon shape in postgis to create a pseudo 3D effect. To this end I have written a crude function to achieve it. This is very much test code and it creates a new Y vertice for ...
1
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0answers
53 views

Collection of polygons from a collection of points

I have a set of points, spread over a wide geographical area. I need to be able to create a set of polygons which best represent the clustered points. And I would like to create the clusters based on ...
0
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2answers
194 views

st_multi equivalent in Oracle spatial / how to convert polygon to multipolygon?

is there an equivalent to the PostGIS ST_MULTI available in Oracle Spatial? or - How can I convert POLYGON to MULTIPOLYGON in Oracle spatial? Regards, D
1
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2answers
175 views

Automatically create polygons from top right and bottom left coordinates?

I have a CSV file with hundreds of records. Each record contains 2 matching coordinates, 1) top right corner of a rectangle, 2) bottom left corner of a rectangle. Polygon ID, Lat 1, Lat 2, ...
3
votes
3answers
656 views

Remove slivers from merged polygons

I am creating a single polygon by merging different polygons in ArcMap. When I merge them, slivers are created. So I have to delete those slivers manually. I don't have a license for ArcInfo so tools ...
1
vote
1answer
621 views

combine several polygon objects in one polygon object with geotools (is it possible)?

I have several polygon objects and I need to "merge (or combine or dissolve)" them toghether into one polygon object. With a GIS tool like Quantum GIS, I do this with Geoprocessing option "Combine ...
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0answers
337 views

Topography: How to convert raster into vector layers?

(nb:This project is part of the #Wikipedia #wikimaps project) 1. Question: How to create vector topographic maps from raster image ? How to convert raster topographic image into closed vector ...
2
votes
2answers
126 views

Tool for Creating Polygons

Does anyone know of any tools that exist for creating a polygons. I need to provide some employees with the ability to create shapes that detail the boundary of certain locations. So I just want a ...
0
votes
1answer
252 views

How to remove shapefile polygon vertex marker points in QGIS 1.8.0

I have created a shapefile layer and drawn a polygon to show the boundary of a woodland. How can I edit the polygon to remove the crosses that denote the intersection of two points on the boundary?
2
votes
1answer
62 views

POLYGON25D WITH OGR2OGR

I know how to convert a csv file with xyz coords to point25d with ogr2ogr and vrt file but the coords in the files are the vetices of 3dpolygon (firsth and last ones are the same coords). I want to ...
4
votes
1answer
203 views

How to generate overlapping polygons from lines output from Table To Ellipse tool?

I have a feature class of line-based ellipses generated by the Table to Ellipse tool that looks like this: What I want is polygons of the individual ellipses, however tools like Feature to Polygon ...
3
votes
2answers
1k views

Colouring areas between (vector) contours?

Is it possible to colour areas between (vector) contours without making it a DEM first? Joshdoe seems to have done so in Create filled contour map with GRASS but does not say how.
4
votes
1answer
519 views

create grid cells of fixed dimension around a point acting as a centroid

I've been trying to solve a problem for the last few days but not having much luck. I'm hoping someone here can point me in the right direction. I'm new to ArcGIS so I hope my explanation makes ...
3
votes
3answers
458 views

What Is The Ideal Workflow To Map (British) Postcode Territories

I'm looking for the best workflow for mapping postcodes and calculated territories, but being relatively new to mapping I'm struggling on a few details and also the best practices for displaying these ...
0
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0answers
112 views

How to draw polygons around known clusters

I need to split up an area into non-overlapping, but contiguous territories. I have n points on a map, which are partitioned into k sets. The partition is only partially geographic, meaning that ...
7
votes
2answers
178 views

Generating polygonal blocks using growing lines

We first generate a set of locations (i.e., points(x,y)), randomly. Then we assign for each point a number showing the angle of a line being centred at that point. The criteria for the length of lines ...