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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2
votes
1answer
309 views

How to split Polygons by line grid?

I want to split a polygon by a intersecting line into different parts, exactly like in this post(Qgis - Is there a way to split a polygon layer with a line layer?). I have a vector grid to cut the ...
0
votes
2answers
169 views

Tool for rendering/drawing maps from coordinates

What tools can be used to convert a set of coordinates into polygons? For example: this code represents a room by providing information about it's four corners. <node id='-202' lat='41.015146' ...
2
votes
1answer
190 views

Retrieving points that make up drive-time polygon generated by ArcGIS for Desktop in automated way?

One of our GIS guys showed me a demo of the ArcGIS Network Analyst extension creating a drive-time polygon for points that he clicked on a map. This is exactly what we need for our web application, ...
1
vote
2answers
2k views

accurately find the bounding box of geography polygons

Im displaying polygons on a map and have had issues with the spatial index where the index performs well only for certain data sets (large areas with low density / high density small map areas). I've ...
2
votes
1answer
353 views

Appropriate pixel size when converting vector to raster

I am converting vector polygons into raster datasets. Is there a standard calculation for converting the scale of the vector into an appropriate pixel size (e.g. 25 metres)? My vector has been ...
1
vote
0answers
205 views

Merge overlapping GeoJSON GeometryCollections

I need to merge three overlapping GeoJSON GeometryCollections of Polygon. Ultimately, the end result needs to be a geom type for PostGIS (e.g. MULTIPOLYGON) so I can easily check if particular points ...
2
votes
2answers
180 views

QGIS polygon centriods - How are they created?

I have been using QGIS to analyses spatial data and I created polygon centroids with the vector geometry tools. Now for a report I have to explain how these centroids were created. I have not been ...
0
votes
1answer
271 views

ggmap fortify start and end jumble

I have a census tiger line file for counties available from the Census website. I am trying to display this file on a ggmap, but fortify seems to jumble the regions. I can't find anyone else who has ...
0
votes
2answers
845 views

Convert polyline to polygon Using ArcObjects

I have a polyline and I want to convert it to a single polygon feature,I used this code but I get error while I can convert the same shape file using feature to polygon on ArcGIS Where is my mistake? ...
0
votes
3answers
132 views

Same size polygons giving different overall areas

I am currently working with multiple shape files that I have clipped to the exact same extent, but when I calculate area (acres) within each polygon. I am getting different results between the ...
1
vote
0answers
246 views

How to understand google map overlay type from object (polygon or polyLine)

var Line = new google.maps.Polyline({ path:predectionArray, editable: false, strokeColor: '#FF0000', strokeOpacity: 1.0, strokeWeight: 2 }); var Rect=new google.maps.Polygon({ ...
0
votes
0answers
186 views

how to remove a point or polygon in shapely python

I want to place minimum number of sensors(circles) to cover a maximum area(polygon). I am using "Shapely",python module. I want to know if a sensor i.e a point buffer inside the range of the other ...
2
votes
3answers
208 views

Find closest point between polygons inside other polygon

I have access to ArcInfo (ArcGIS 10.1). The dark polygons are settlements. The green polygon is derived from a suitability analysis. The surrounding white area is restricted. I want to find a point ...
0
votes
1answer
119 views

gdal_rasterize : getting area not in or touching polygon (options -at and -i)

I would like to capture the area that is not in a polygon (option -i) and that doesn't touch that polygon. gdal_rasterize -at will return the polygon + edges, but gdal_rasterize -at -i will not ...
6
votes
1answer
7k views

Cut polygon shapefile by line shapefile

I have two shapefiles, a polygon shapefile (lake) and a line shapefile (boudary) I want to create a new shapefile "polygon to the north of the boundary" What tool can I use in QGIS or other free ...
2
votes
2answers
195 views

Check if a single feature is completely within another (arcpy)

I have a feature class that contains one polygon feature, and I need to check if said feature lies completely within another polygon feature. Used selectLayerByLocation and then retrieved the count ...
1
vote
1answer
1k views

Iterating over all features in featureclass to intersect them individually with polygon using ArcPy?

I've got a point featureclass, and I'm trying to individually intersect each feature with a polygon featureclass to get some information about which polygon each feature is in. I did one intersect ...
2
votes
0answers
125 views

CartoCSS: Don't show border between adjacent polygons

In OSM, riverbeds are created as multiple adjacent or even overlapping polygons. When styling these polygons in CartoCSS with a border, the overlapping can be seen: I'd like to hide that line ...
-2
votes
1answer
54 views

How do I get the Coordinates of a shapefile into .csv [closed]

I have followed all the instructions on this site, but my output always shows Area, and Perimeter of each polygon. Am I missing something? Should I be changing a setting somewhere to select ...
1
vote
1answer
254 views

Calculating distance of polygons from coastline using ArcGIS for Desktop?

I have a series of polygons representing parcels of land. I would like to calculate the distance of each polygon from the coastline. I also have a polygon of the entire region of interest, i.e. an ...
1
vote
1answer
377 views

XY data in sketch properties

Does anyone know if there is a way to export the xy data from sketch properties in the editor to a .txt file?
4
votes
1answer
510 views

Changing raster cells values inside of a polygon to the closest cells just outside the polygon!

I have been wrestling with this for a while and couldn't find out how I can do this. I want each cell of a raster inside of a polygon boundary to have the value of the closest cell just outside of the ...
0
votes
1answer
155 views

Millions of polygons: displaying layers in Leaflet based on location being viewed?

I'm trying to create a map of all parcels in a state. In my state, this is several million parcels. In their current format, they are encoded as topojson and divided up by county. I'd like to show ...
1
vote
1answer
582 views

Calculating percentage of polygons within specific areas using ArcGIS for Desktop? [closed]

I have a parcel layer and I am trying to determine the percentage of each parcel that falls within specific zones. I tried tabular intersect but it just returned an empty output. I'm using ArcGIS ...
0
votes
1answer
212 views

converting random point order into polygons

We received a kml file with polygons but the points are not in a logical sequence and we end up with strange overlapping shapes that are supposed to be an open polygon. We did identify a point near ...
0
votes
1answer
116 views

Find polygons that contain a specific number of points

I want to make a polygon selection based on a specific number of points. For example, I want to select those polygons that contain more than 30 points. I don't want to select every polygon that ...
0
votes
1answer
836 views

How to calculate point from lat/long, angle, and distance? [duplicate]

I am trying to calculate the point from a given lat/long, a bearing, and a distance. This is for plotting weather given a aeronautical way point. For example: Given a waypoint with a known ...
4
votes
2answers
1k views

What methods exist for geohash of polygon?

GeoHash is an excellent method to code the latitude and longitude of a point into a string. It's concise, due to the use of numbers + letters, and the precision can be tuned adding characters at the ...
1
vote
1answer
109 views

PostGIS: Update child geometries based on parent

I'm using Leaflet and postgis in a case where using Leaflet draw plugin I draw a polygon first like this Now, I draw a line which cuts the polygon and using line and polygon geometry, based on ...
2
votes
1answer
1k views

Step-by-step: How do I extract Raster values from Polygon overlay with Q-GIS or R?

I am writing my master thesis at the moment and am having the exact same problem as user Curley in this question: I first need to overlay a Corine 2006 raster with a polygon layer (2638 polygons). ...
0
votes
0answers
19 views

Created polygon appears to move when zooming in (qgis)? [duplicate]

I am using QGIS 2.20 on a Windows 8.1 64-bit laptop. I have a shapefile that includes a polygon that I created from digitizing a Google Satellite image from OpenLayers Plugin. Here is my problem: ...
3
votes
1answer
161 views

Is there an alternative to the Integrate tool that will not change one of the inputs

I have two polygon layers, and would like to snap the outlines of one of them (colored poly's) to the other (grey) without changing the grey in anyway (so Integrate seems out). It should only snap if ...
1
vote
0answers
38 views

Reclassify based in neighbour polygons

I would like to do a simple operation in QGIS and I am not sure about which is the best option. I have a polygon shapefile and each one has one class attached. I want to reclassify one of them based ...
0
votes
1answer
99 views

Extracting info on polygons from underlaying raster layers

In ArcGIS 10.1, I have two layers: 1) raster of Topographic Wetness Index 2) vector layer of polygons representing soil types I am wondering how to accomplish what I am after, that is to get ...
4
votes
3answers
317 views

How to compute the outline of multiple tracks?

I have multiple gps tracks with depth data gathered from the lake. The tracks are overlapping/intersecting. I want to get an outline polygon. I have a multi-line shp. I've tried to diffuse it in qgis ...
8
votes
1answer
246 views

Suitable algorithms for simplifying isochrone polygons

I'm looking for an algorithm for simplifying isochrones which were generated using OSM data. These are generally characterised as having lots of small "holes" mostly due to missing OSM data but also ...
4
votes
2answers
144 views

“Levelling” elevation data coinciding with polygon?

I have a shapefile containing building geometries (polygons) and a elevation dataset. The elevation data doesn't perfectly match the buildings. I want to "flatten" the elevation data so that ...
2
votes
1answer
249 views

Smoothly interpolating Polygons from set of coordinates?

I'm still quite new to QGIS and I'm using it to display and analyze my soil data. I have point information on the distribution of the soils in a specific area and I need to create a soil map from ...
2
votes
1answer
172 views

Spike finder in PostGIS

I tried to modify spikeRemover from Schmidt & Krüger. My goal it's to obtain, for each polygon, the position of the spikes. I don't need to remove it. For some reason, that I can't figure out, my ...
2
votes
2answers
969 views

Change points to polygon

I have a map which has one data point per zip code. I would like to change those points to zip code polygons. Any ideas on how to go about it?
2
votes
1answer
164 views

Is there a way to clip a polygon layer according to DEM elevation?

I have a polygon layer on top of a DEM. Is there a way to clip the polygon layer according to elevation, ie the clipped result being only those areas of the polygon layer between x and y altitude? ...
-1
votes
0answers
32 views

what is the math behind rasterization? Doubt [duplicate]

In Figure 4 you can see how the overlap is not complete (marked with circles). What I would like to know which algorithm that QGIS uses the rasterization? What is your standard? Is there a percentage ...
0
votes
1answer
244 views

Extract address data / Query point in administrative boundary

I try to create a DB in postgreSQL with all the postal adress data for a specific country. Actually I have this table full of data: id integer NOT NULL DEFAULT nextval('plz_id_seq'::regclass), ...
1
vote
1answer
282 views

Get Coordinates of Voronoi Polygon Vertices [duplicate]

Is there any chance to get the exact coordinatas of the voronoi polygons? I am using Qgis software and I have the "center" (redpoint) of the polygons and I would like to export the polygons corners ...
-1
votes
1answer
128 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 ...
2
votes
2answers
218 views

zoom over vector in leaflet

I have created a map from geojson file of administrative boundaries (polygons layer). Similar to this example. When the mouse is over the polygon feature, the cursor changes from hand to finger. In ...
0
votes
1answer
122 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 ...
1
vote
1answer
52 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.
0
votes
2answers
195 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
211 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 ...