Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [polygon]

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.

2
votes
1answer
128 views

Use QGIS or QField with a GPS physically walk a polygon in the field

Is it possible to use QGIS or QField with a GPS to physically walk a polygon in the field? I'd like to use the software to physically walk shapes in the field but have been unable to find information ...
3
votes
1answer
93 views

Sorting features in legend

I have a map with a polygon layer containing 100+ features. I want them to display on the legend and the Layer Tree using the Polygon's ID and then its name i.e: "Id - Name". I'm using the ...
3
votes
3answers
318 views

Converting CSV (polygon coordinates) to polygon feature class (shapefile)?

I have a CSV table as following : ID;POLYGON 1;(-7.59443,33.55933):(-7.59416,33.55937):(-7.59414,33.55922) 2;(-7.58361,33.56655):(-7.58148,33.56655):(-7.58148,33.56486):(-7.58361,33.56486) The ...
2
votes
1answer
49 views

Drawn polygons in QGIS (3.2) are not accurate in ArcGIS Online?

I am drawing polygons in QGIS (see figure 1), but when I import the shapefile to ArcGIS Online, it does not look like what it is on QGIS (see figure 2). Instead of being an intricate polygon, its all ...
0
votes
1answer
62 views

Extracting vertices in line segments using ArcGIS Desktop? [closed]

I have ArcGIS Desktop 10.6 and have many polyline features and want to be able to extract the vertices of each line segment that looks like this: I want to keep the line ID associated and be able to ...
1
vote
1answer
2k views

Create a polygon from coordinates in GeoPandas with Python

I was trying to create a simple Polygon from a list of coordinates and export it to multiple formats (including shapefile and GeoJSON) and wanted to automate it using Python. There were some good ...
0
votes
1answer
32 views

Cutting rasters using polygon and obtaining pixel specific data using ArcMap

I have a georeferenced polygon file that I want to use to cut several different raster files. I am looking to analyse the individual pixels within those cut areas. One of the raster files has a ...
3
votes
1answer
100 views

How to plot a point on the highest elevation of a raster on a polygon. QGIS

I have a shp with more than 1700 polygons on a elevation raster. I need to plot a point that represents the highest altitude location within the polygons, and then export those points as a new shp.
1
vote
0answers
38 views

Removing dateline in polygons

I am using the marine boundaries data from MarineRegions.org and I'm trying to use cylindrical equal area with a -160 central meridian. I successfully removed the dateline from polygons basically ...
0
votes
0answers
33 views

Creating 25k Grids With The Fishnet Tool - Having Trouble With The 25k Part

I've created a script (my first script, in fact) that asks the user to provide a shapefile and then runs the fishnet tool to create a grid overtop said specified file. Problem is, for some reason I'm ...
0
votes
0answers
31 views

Arcgis Pro's Eliminate not eliminating selected polygons?

I'm trying to use Eliminate to reduce the number of polygons in my dataset that have a very small area size. As far as i understand the tool, you have to first create a selection in the dataset, and ...
3
votes
1answer
247 views

Filling gaps between polygons using QGIS?

Here are my polygons of town blocks. The colored towns are considered as areas where they have the same post code. What I eventually want is to make seamless polygons where there are no gaps between ...
0
votes
1answer
275 views

Why does mysql ST_WITHIN work for some MultiPolygons but doesn't for others?

The mysql queries are to return all POI's within a certain country. This works (for Angola): SELECT poi.poi_id, poi.poi_address_full FROM poi WHERE ST_WITHIN( poi....
1
vote
1answer
26 views

QGIS Union erroneously creating gaps

I'm trying to do a union between two Polygon Shapefiles, but when I do Vector > Geoprocessing Tools > Union I have the odd issue where most of it works fine, but some areas are returned in the union ...
1
vote
1answer
48 views

Generating centerline for polygon using ArcGIS Desktop?

How could I generate a nominal centreline for a polygon and then generate lines perpendicular to this centreline at regular intervals? I've explored generating a centreline using the tools here: http:...
1
vote
1answer
58 views

Decrease polygon vertices count maintaining its aspect

Is there an algorithm or technique that allow me to decrease the number of vertices of a polygon while maintaining it at some acceptable aspect? The problem: I have a functionality in my system (...
0
votes
2answers
49 views

Calculating width of polygon relative to polyline using ArcGIS Desktop?

I need to estimate the different widths of the polygons that surround some polylines. The polygons correspond to wetlands (buffer zones) and the lines represent the rivers. The catchment that I´m ...
0
votes
0answers
126 views

What msqyl field type to use for polygon and multipolygon city/country geojson from geonames

Which mysql field type should I use to store country and city boundaries? Mysql version: 5.7 Data source: Geonames shapes_all_low.txt (http://download.geonames.org/export/dump/) Issue: In this ...
2
votes
2answers
143 views

How to polygonise a large and detailed raster into a single valid polygon with QGIS?

I am doing research on the protected areas of the Amazon rainforest and I need to create a single polygon layer that has all the forested non-protected areas in one attribute row. I have tried using ...
0
votes
0answers
9 views

Polygon Multiple FID attribute for one

I am using ArcMap attempting to find the total area of this multi-part polygon, however in the attribute table there are multiple FID corresponding to the same polygon. They all have the same acreage ...
2
votes
1answer
38 views

Merge/Dissolve Polygon overlapping within

I have a polygon that has been broken down to an intersecting analysis point. Each segment has its own acreage within an acre field on the attribute table. I want the intersecting lines to be removed ...
0
votes
1answer
58 views

GDAL ogr2ogr OracleSpatial to Shape: Multipolygons with wholes/multiparts are missing

We're holding geodata in an Orcale database (11g) with spatial extension. I want to unload specific polygons and convert them into Shape for further local processing. The table where I'm unloading ...
0
votes
1answer
203 views

Getting attribute from overlapping feature from other polygon data using ArcGIS Desktop?

How do I transfer attribute data from one polygon layer (A) to another (B)? I am using ArcMap 10.2. I tried using Identity. It doesn't work. I also tried converting (A) to point so it has the same ...
0
votes
0answers
22 views

Polygon interpolation neighbour average?

I am trying to estimate empty values based on a polygon layer we received from another study. Is there a way to calculate an average value for polygon A based on neighbours B,C, etc that border it? I ...
1
vote
1answer
59 views

Change attribute of a line according to overlapping polygon features

I'm pretty new to QGIS and python in general. For my work I'm faced with a bit of a problem. I got 100-m-segments of several streams and polygon-features of the surrounding substrate. The polygon ...
0
votes
2answers
159 views

QGIS remove useless vertex to simplify polygon

I received a shapefile which is the result of a combination of several polygon. I want to clean and simplify it as there are many useless vertex as you can see on the picture. This is only one feature ...
0
votes
0answers
26 views

Using tabulate intersection tool to determine percent forest cover in polygon grid cells

I feel like this should be relatively straight forward and yet I've been having issues each time I try to do this. Essentially, I have a polygon layer of land use classes (two of which are of primary ...
0
votes
0answers
51 views

How to create sector polygon for a given point feature at a given radius (1000 Km), and direction using ArcPy code?

I want to create polygons of sector shape for many point features. Each sector has central angle of 90 degrees and radius of 1000 Km. How can I create it using ArcPy code? Here is my approach that I ...
1
vote
2answers
112 views

Summing values from multiple polygons per neighbourhood in QGIS?

I'm measuring different values of urban parks (groundwater recharge, CO2 sequestration etc.), assignning values to the park polygons as attributes of a layer. Now I would like tu sum them up to have ...
0
votes
2answers
95 views

Shapefile from heading and distance directions for property boundary

I have a survey with heading and direction points describing the boundary for a rural property in Brazil. I am in correspondence with someone there who needs a shapefile (I believe he mentioned kml or ...
2
votes
2answers
243 views

How are the coordinates for multipolygons arranged?

How are the coordinates for a multipolygon (i.e. polygon with a hole in it) arranged? Do shapefiles and geoJSON files always save the coordinates for the outer ring first? I'm asking because I ...
1
vote
0answers
38 views

Create x,y points with a radius that best fill a polygon

I am looking to best fill a polygon with non-overlapping circles of a specified radius and then extract the x,y points from a table. Is there a way to do this in MapInfo without specifically picking ...
0
votes
1answer
70 views

How to get parcel boundaries with tax roll, land use, and zoning info?

How do I get parcel boundary shapefiles with tax roll, land use and zoning info included? Is it possible to just create the parcel boundaries data from scratch, i.e. could I create parcel polygons in ...
0
votes
2answers
277 views

Remove internal boundaries in spatial object/polygon for plotting

I am trying to plot a spatial object where only the outer boundaries/borders are plotted. The only way I can think to do this is by manually removing all the lines/points within the spatial object and ...
0
votes
0answers
35 views

How to create a donut polygon in Openlayer 3

function Draw(coordinat, c) { var geojsonObject = { 'type': 'FeatureCollection', 'crs': { 'type': 'name', 'properties': { 'name': 'EPSG:3857' } }, '...
0
votes
1answer
55 views

Cutting out polygon from other polygon / removing clip

I have a polygon that shows a lake. I have a second polygon that contains districts. I want to cut out the lake so only get the bits of the districts that is on land. I tried clip, but I think I ...
1
vote
1answer
42 views

Cut out polygons that at least partially fall in another polygon?

I have a large polygon shapefile that describes a river catchment. I also have another polygon shapefile that contains a number of smaller polygons that represent districts. I would like to create a ...
2
votes
2answers
148 views

Cartographic generalization: Dissolve “neighbour” / bordering polygon objects in QGIS

I have a polygon layer with buildings for the area of the whole city. My question is how to dissolve/aggregate/merge only those buildings, that are "neighbours", in a sense that they share at least ...
1
vote
1answer
60 views

JTS: generate a polygon geometry from line geomtry

I have a line and I wish to convert it to a polygon. The point is this line is NOT a ring it's an straight Line. And I want to use an specific width to extend line horizontally and create a polygon. ...
1
vote
1answer
56 views

Euclidean distance and connecting lines between polygons using ArcMap?

I have a large set of polygons. I want to (1) calculate pairwise distances between polygons (so one polygon should be connected to several others). I can do this using the generate table in ArcMap. ...
3
votes
1answer
844 views

Is it possible to convert Polygon to centerline linestring?

I have a Polygon which I want to convert to centerline linestring. IMAGE 1 I used the Vector to convert to Polyline but they are not center line as under: VECTOR TOOL IMAGE 2 Polyline created by ...
0
votes
1answer
64 views

Transforming a polygon to a linestring

Is it possible to (trivially, via a tool in python) to convert a polygon to a linestring? if so, how? If not, why?
0
votes
0answers
33 views

Automatically Trigger write fields from polygon to point when adding point

When editing, I would like to create an SQL trigger that will write fields from my parcels layer to a point layer that the end user is editing. Essentially, when a point is placed on a parcel, that ...
0
votes
1answer
34 views

Extracting pixels from polygonal geospatial region of set of map tiles and/or set of GeoTIFF files?

I need to create a script, probably JS or Python, to perform the following: I have a polygonal region -- no "holes", and always fully convex -- for which I need to extract the pixel data from one of ...
3
votes
2answers
315 views

How to create a polygon from Excel coordinate file

Currently I have an Excel file with 2 columns. area number. coordinates. The coordinate column contains several X and Y points those are seperated with a comma. Next an example how the points are ...
-1
votes
1answer
33 views

Drawing polygons with holes on map using vertices exported from QGIS?

I have exported from QGIS, for a feature in a layer, all the vertices (lat and lon) of a polygon, into a file. I'm trying now to draw that polygon using that list of vertices (that I re-read from the ...
0
votes
0answers
28 views

Openlayers - Updating style of overlapped polygons

I made a javascript which reads geojson files, depending on a period selected by the user. These files contain polygons which I display on a map. For now, I've been able to make them transparent in ...
1
vote
0answers
171 views

Fix zip code polygon?

How do you go about correcting USPS Zip Code polygons? I have an address with a zip code assigned and recognized by the USPS. However, when I look at the USPS Zip Code polygon map I see the wrong ...
0
votes
1answer
29 views

Creating a polygon outside another but using existing as boundary

I need two polygons. I already have one (the river edge boundary as seen below) What i want to do is create another polygon which covers the part of the raster which does not fall inside the river ...
0
votes
0answers
116 views

Intersect a linestring with a collection of polygons in Shapely

I have a LineString that represents a trajectory and a Python list of Polygons that represent crossroads. I would like to insert new points into the LineString wherever it crosses any of the polygons, ...