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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-1
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1answer
81 views

Determining if polygon contains point to populate point's field with polygon's name using arcpy.da?

Am trying to check if the points in a point shapefile are contained within a polygon shapefile and if so, to populate a field in the point shapefile with the name of the polygon and to populate the ...
8
votes
3answers
3k views

Using polygons to apply unique value to all raster cells within those polygons?

In ArcGIS 9.3, I have a raster file that I would like to "mask" with polygons, giving a single value to all the raster cells that overlap the polygons. How can I do this? Here's a screen shot, ...
0
votes
2answers
114 views

mapbasic, create polygon, insert node

Hi I try to create a parsel table from coordinates. My scripts are below. Why it does not show the results on the map? Thank you in advance! Create Table "parsel" (Parsel_Adi Char(10)) file ...
1
vote
1answer
89 views

How to close spaces within a polygon in QGIS 2.2?

I have a shapefile displaying the borders of several city units. One of its polygons, however, had free space consisting of four vertices in it. I created another polygon inside the free space and ...
0
votes
1answer
80 views

How to add point attributes to containing polygon?

I have three layers in a QGIS project: layer 1 is a boundary layer of polygons each with and id I will call "p_id" layer 2 is a point layer each with an id called "p_id" layer 3 is a .csv layer ...
0
votes
1answer
45 views

How to select a specific area (in a polygon form) determined by some value range in a raster band?

For example, I want create a vector layer with polygons that represents all areas where the elevation is between 500 and 600. Someone has any idea to help me? I'm using PyQgis 2.2.
11
votes
5answers
6k views

How best to fix a non-noded intersection problem in PostGIS?

I'm using a PL/R function and PostGIS to generate voronoi polygons around a set of points. The function that I am using is defined here. When I use this function on a particular dataset I get the ...
0
votes
1answer
95 views

QGIS convert polyline to fixed width polygon

I have a shp file of polylines for trails, and I need to convert them all to be polygons that are 8 ft wide (4 ft from the center of each side of the polyline). I tried a following a few other posts ...
3
votes
1answer
1k views

Problems converting polygon to point [closed]

I'm trying to convert polygons to points with ArcGIS 10. My polygon layer has 2 attributes that I want to give to my point layer. I'm using the Feature to Point function from the Arctoolbox, but it ...
0
votes
0answers
74 views

Draw polygon shape via Qbutton

Ideally; a Ui Qbutton is needed that will activate map canvas editing to add a polygon via the classic mouse click rubber band method. Upon a concluding right click with the active tool, editing ...
3
votes
2answers
191 views

Double (triple, quadruple) size of polygon using ArcGIS for Desktop?

I have several polygons, measured in acres. I'm looking to double the area, either by a buffer, or some other method. I will need to triple and quadruple in the end, as well. I have tried to use ...
0
votes
0answers
30 views

Error while importing data from GSHHS_f to MySQL database

I'm doing a summer project on geospatial development using python and I've been following the book Geospatial Development Using Python by Packt Publishing. The thing is, I've tried to import the GSHHS ...
1
vote
1answer
49 views

Rectangle polygon is displayed as triangle

i am wondering why a rectangle polygon that i have created on an official german surveying website (downloaded as compressed shape in a zip-file) is displayed as a triangle when loaded in qgis. mighty ...
2
votes
1answer
142 views

How to surround a Polygon object with a corridor of specified width?

I'd like to build a corridor surrounding a polygon, so that the corridor's outer bounds all have the same distance to the inner bounds. Like this: I've made this lousy graphic in Paint, since I ...
0
votes
0answers
156 views

QGIS Intersecting polygons

I have two different shapefiles, each with polygons for one country. I want to find out which polygons of one shapefile are part of the polygons in the other shapefile. For example Polygon 1 of ...
1
vote
0answers
56 views

Authoring map with advanced gradient symbol for ArcGIS web service?

I need to prepare a web service which will display the gradient of polygon points values. It has to look just like in this picture: link to the picture (please ignore the arrows). Each polygon is ...
3
votes
1answer
184 views

FME: Using WorkspaceRunner to batch 2 readers

I need a little help using the WorkspaceRunner in FME. Essentially I want to batch run polygon shapefiles in one folder (30 of them) against another load of files, in the form of a tiled grid (26 ...
0
votes
2answers
140 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 ...
0
votes
2answers
81 views

Joining two polygon layers based on distance?

I'm new to GIS so this question may be an obvious one. I have one polygon layer of urban land use and another polygon layer of swamps. How do I join the two layers so that I get a column in the ...
0
votes
0answers
86 views

Determine the list of circles (from 100K circles), that overlap with a given polygon

This question was asked on StackOverflow, came here because no response has been posted so far. Existing data structure we have polygons represented as an ordered list of lat/long coordinates and ...
8
votes
1answer
1k views

Splitting landcover polygons (parcels) into equal sizes, while retaining road access for all?

I would like to split landcover polygons which surround a road polygon into equal sizes, while ALL resulting polygons should have access to the road! Is there any chance to do this automatically? ...
0
votes
1answer
162 views

Setting a value on a raster where a polygon intersects cells

I reviewed all of the supposed 'answers' and I just do not see that they really answer my question. Mostly because the ones I'm reading are setting values either inside or outside a boundary. So let ...
1
vote
1answer
102 views

How to compare multiple spatial point patterns over a polygon

I have multiple point pattern distributions over the same region/polygon. Each point pattern distribution has different number of points. Here is an example of two spatial point patterns for the ...
1
vote
1answer
321 views

Intersect between polygonal shapefiles error

I'm encountering a problem when I try to intersect two different shapefiles. They are all new shapefiles I created to descibe the land cover and the land use of a city. The problem occurs when I ...
0
votes
1answer
46 views

Find extent of data inside many polygons

This is similar to Calculate polygon area inside extent I have a few different polygon datasets which describe things like soil type, bushfire risk etc. For each property boundary we want to see how ...
0
votes
0answers
97 views

How to split an oblong, irregular polygon layer into even pieces?

I have a polygon layer (landuse) that I want to split into 100 meter pieces. The polygons show landuse along a road. I want to split the polygons layer so that I can then calculate the percentage of ...
4
votes
2answers
2k views

How to Polygonize a polyline shapefile in QGIS 2.2?

When I used QGIS 1.8, I was able to transform polyline layers to polygon layers with the Polygonizer plugin. In QGIS 2.2, this function has been subsumed into the Processing toolbox. Unfortunately, ...
0
votes
1answer
295 views

Get the outer ring inner ring for a given polygon using ogr python binding

I am trying to read the geometry of some shapefiles, now I meet some problem when I try to identify the polygon with holes, since a polygon may(or not) have one hole(or multiple holes). This is the ...
0
votes
1answer
451 views

Search for geojson polygon in mongodb implementing a custom vector tileserver

I am building a vector tileserver in node.js using mongo 2.4.7 as database. My database contains geojson data from multiple sources and they are in many layers. It is important to render the layers ...
0
votes
2answers
1k views

How to get WKT or GEOJson by country or city name with Overpass API?

I'm trying to understand Overpass API, I'm experimenting with it, but cannot get what I expect. Overpass API doesn't return me neither polygon shapes, nor WKT, nor GEOJson, nor even a highlight of the ...
21
votes
3answers
5k views

How can I calculate the average width of a polygon?

I'm interested in examining the average width of a polygon that represents the road surface. I also have the road centerline as a vector (which is sometimes not exactly in the center). In this example ...
2
votes
0answers
59 views

Does converting polygon to raster generate more accurate results from the Zonal Statistics in Arcgis 10.2

I have heard the following for Arcgis 9.1 and wonder whether it is still an issue in Arcgis 10.2. If so, should I convert the polygon into raster before dissolve or convert the dissolved polygon ...
2
votes
1answer
1k views

Calculating the outer boundary of several Geometry objects in SQL Server 2008

I have lots of Polygons of datatype Geometry in SQL Server 2008. The image below shows how a select of all these Geometrys looks visualized. What I need to do is create a Polygon which represents ...
1
vote
2answers
442 views

MySQL Polygon (Spatial) Insert Statement works sporadically

I know that MySQL doesn't have great spatial support at the moment, but is it that buggy that my insert statements would work sporadically? In general, longer coordinates seem to be failing on insert ...
6
votes
2answers
14k views

How to combine adjacent polygons sharing similar trait into single polygon?

I have a large dataset of habitat classes which I have further simplified down into my own unique classes. However, it resulted in there being habitats adjacent to each other with the same forest ...
10
votes
5answers
6k views

Performing a reverse clip in ArcMap?

Is there a way to perform a 'reverse' of the clip function in ArcMap, I'm not exactly sure how to explain this so here's a diagram:
4
votes
3answers
4k views

Openlayers remove previously drawn polygon on starting to draw next one

Objective: At any point of time there SHOULD only be zero/one polygon(s) on a vector layer with a polygon control. I need the previous polygon to be removed as soon as user starts drawing the first ...
1
vote
1answer
277 views

How to limit Create Fishnet extent by mask & carry over attributes?

I have a 5km polygon grid of an area which is not a standard square/rectangle, it is in fact a rough ovoid made up of around 500 5km2 cells. What I want to do, eventually, is have a 100m polygon ...
2
votes
3answers
254 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 ...
0
votes
2answers
172 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 ...
0
votes
0answers
55 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 ...
1
vote
1answer
543 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 ...
1
vote
2answers
234 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 ...
1
vote
1answer
641 views

How can a place a point symbol on the center of a polygon?

I'd like to symbolize polygons with a point at the centroid. Does anyone have suggestions how to accomplish this without creating a new shapefile? I'm using ArcGIS 10.0.
1
vote
1answer
120 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
vote
1answer
98 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 ...
0
votes
2answers
112 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 ...
1
vote
2answers
405 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
307 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?
3
votes
1answer
75 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 ...