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.

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2answers
28 views

Calculating areas in continuous raster of flood map?

I generated a flood hazard map (raster) of a certain area using ArcGIS 10.5 and classify the result into low 0.1 ÷ 0.5 medium 0.5 ÷ 1.5 high > 1.5 After that, I overlay a Land Use map (...
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0answers
35 views

Is it possible to merge two polygons with a single touching point into one?

Is my understanding correct, namely that two polygons touching at a common point cannot be merged because the result would be a self-intersecting polygon? I know there are dozens of Q&A threads ...
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1answer
50 views

Snapping to sketch' vertices while editing in QGIS?

I'm trying to digitize buildings in QGIS and encountered a problem: after digitizing several vertices in a sketch, I want to place my final vertex in accordance with the first one - i.e 'square and ...
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0answers
11 views

ArcGIS Pro - need to import 3D model then create polygons on 3D model to measure sections for surface area

I am generally new to ArcGIS Pro. I am working on a project using photogrammetry where I am reconstructing 3D models and trying to measure the surface area of different sections of the models. Maybe I ...
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1answer
66 views

Create GeoJSON Feature from FeatureCollection

I have a single polygon feature (no holes, no overlaps) which is currently defined as a FeatureCollection in GeoJSON, with type Polygon (not MultiPolygon). I am trying to use it with an online mapping ...
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0answers
7 views

Is it possible to assign values from polygons to a new layer in an existing raster in R?

I'm a bit of an R novice and looking to see if there is any way to assign values to a raster layer based upon polygons. Some background - I am working on a mining project and have a regular grid of ...
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1answer
31 views

Draw a polygon in OpenLayers with coordinates from a variable?

I have the polygon coordinates defined as a variable. This draws nothing when I use the variable, when the same coordinates are used as such in the polygonFeatureT definition, the polygon is drawn ...
2
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1answer
98 views

Finding centre line of irregular polygons with QGIS?

I have a set of irregular and curved polygons which I would like to find the centre line of them. I've found some solutions for this problem such as Voronoi polygons but It doesn't work for me. It ...
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3answers
1k views

Voronoi Diagram on a given polygon using QGIS

I am trying to create a Voronoi Diagram on a specific polygon, but there is some issue when dealing with edges. Here is how I do it: Preparing the points for Voronoi and the polygon for the diagram ...
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0answers
41 views

Fitting many rectangular shaped polygons into larger irregular shaped polygon in PostGIS?

I am looking to try and find the optimal fit for a number of rectangular shaped polygons into a larger irregular shaped polygon and I haven't found much information about how this could be achieved in ...
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1answer
42 views

Intersecting 2 layers without creating duplication using QGIS?

I have 2 polygons that i wish to combine into one layer, in QGIS. on the first layer (neighborhoods) i have bigger areas (that divide a city to 7 major areas, or smaller neighborhoods). that i wish ...
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1answer
195 views

Splitting polygons and dividing attribute value proportionally using ArcGIS Pro?

I am using ArcGIS Pro 2.3.0. I have two feature classes (pictured below), RED polygons and BLUE polygons. The RED polygons have a numeric attribute, Value1. How can I split the RED polygons with ...
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0answers
10 views

Creating polygon for each day from table with change of area over time (by day) using ArcGIS Pro?

I have a .csv with data in rows over time (date field and multiple attributes for each day) of the same single area - the fields are high temperature, low temperature, humidity, precipitation. I want ...
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0answers
34 views

Polygon problem with Wacom on QGIS

I currently have a problem on QGIS with my Wacom tablet and polygonal tools. When I create a shape with the polygonal tool, if I use my Wacom tablet, the cursor moves well, but the path (red dotted) ...
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1answer
53 views

Creating coordinate points based on polygon

I am trying to create coordinate points based on a polygon that I've created in Google Maps and imported into R as an sf object. Specifically I have sample points of physical samples I've taken, but ...
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0answers
85 views

Calculating viewing angle (2D) between polygons and points [closed]

I am looking for a solution to the following problem. I have several points (for example houses) and several polygons (eg forests). Seen from the houses, I can see the forests within a certain angle. ...
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0answers
25 views

Selecting only polygons with certain variable in them using ArcMap?

I have green space polygons for London and also illegal pollution areas in polygons in ArcMap. How would I go about selecting only the green space polygons that have pollution areas in them (so the ...
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1answer
20 views

Raster does not clip according to polygon feature

I'm trying to cut my raster to fit a polygon, but it keeps doing this weird thing pictured below. I've tried the following things: Merging and dissolving the polygon into 1 polygon Converting the ...
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1answer
20 views

Removing Overlapping Outlines Within a Single Feature Class

I have a polygon feature that is overlapping itself. Both of the polygons in the image below are from that same feature. I do not want to dissolve the boundaries, but I only want one of the outlines ...
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2answers
84 views

Generating random points within series of polygons according to density using R

I have a city that is made up of a number of wards, each with an unequal population. I would like to generate a set of "random" points within the city, but the randomness is influenced by the ...
0
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0answers
69 views

Using a Wacom Tablet and pen for QGIS, can I pause my free-hand polygon before I am finished, and then continue?

Is there a way to pause the free-hand tool in QGIS so that I can lift the pen off of the screen, and then continue my polygon again when I am ready? I have learned how to pan while free-hand drawing ...
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0answers
46 views

When using a Wacom Cintiq tablet and pen, can you pan while creating a feature using the freehand polygon plug-in in QGIS?

Is there a way to pause the free-hand tool in QGIS so that i can pan and move over the image and then continue my polygon?
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2answers
230 views

Converting list of polygons to multipolygon using shapely?

I have a list of polygons where each polygon is a wkt form as follows: list_polygons = ['POLYGON ((-88.131229288 41.900200029,-88.12973798 41.900104202,-88.129785999 41.894907769,-88.131352409 41....
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1answer
28 views

Finding Rows Inside other Rows

So I have database with which I want to do the following: Find out which other rows are contained within the geometry of the row in question. To keep it simple, I am finding the envelope/bbox of the ...
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1answer
39 views

Transform geometry of polygons

I am new to PostGIS. I'm making a spatial join, but it does not work. From what I saw it is something of the geometry of polygons. My polygons are saved with the "Geom" field like this (Geom geometry (...
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0answers
27 views

My work closed and now I cannot see the Temporary Scratch Layers [duplicate]

This is my first project on QGIS 3.6.1. Over night my computer restarted and updated itself closing my QGIS work.. I created two separate Temporary Scratch Layers and frequently saved it on my ...
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1answer
14 views

Counting (Multi)Polygons Within (Multi)Polygons on same Table

So I have a table with approximately 10k rows, with each row having its corresponding geometry entry. What I am attempting to do is count how many row geometries are contained/within the geometry of a ...
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1answer
81 views

Calculating minimum distance in meters of two polygons (defined in lat/long coordinates)?

I'm new to GIS and I'm a bit lost in the terms and concepts, so I'm not sure I'm asking a valid question, but I need to calculate the minimum distance (in meters) of two polygons which are defined in ...
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3answers
78 views

Converting raster pixels to vector cells?

Is there any way to convert raster pixels to vector cells? I mean each pixel to a polygon. I tried the SAGA tool 'Raster values to points' by choosing cells option instead of nodes option. As a ...
0
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2answers
52 views

Identifying polygons that intersect with another polygon using ArcGIS Desktop?

I have two polygon layers, a vegetation layer and a treatment layer. I want to add a field to the attribute layer of the vegetation layer to indicate if any part of the polygon has been treated (...
4
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3answers
441 views

Identifying polygons that intersect with another layer using QGIS?

Using QGIS, I have two polygon layers, a vegetation layer and a treatment layer. I want to add a field to the attribute layer of the vegetation layer to indicate if any part of the polygon has been ...
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0answers
22 views

Use geometry to join Spatial Dataframe

I have two Spatial Dataframe, the first one is the Paris Polling Stations from 2012, the other is the Polling Stations from 2017. They almost have the same geography, it deffers for 20 polygons (2017 ...
2
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1answer
50 views

Remove edge styles on polygons

I have multiple polygons aligned next to each other. They are colorfilled with "Graduated" style. I have changed "Stroke style" to "No Pen". How can I get the hairline between the polygons to ...
0
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1answer
29 views

Extracting difference between two shapefiles (not symmetrical difference) using ArcGIS Desktop?

I have a shapefile with polygons that portray survey areas (Pink areas in picture below). I receive a new updated shapefile with additional survey areas, and thus new polygons (Green areas in ...
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1answer
74 views

Quickly find all polygons that overlap with two or more polygons in Shapely

I have a set of Polygons (in Shapely) that I wish to find all intersections that are comprised of overlaps of two or more polygons. I have been working based off the code found in this answer. I have ...
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2answers
94 views

How to inverse the orientation of the holes coordinates of a polygon in geopandas

I have a polygon shapefile which I am reading with geopandas. The polygon contains holes. My purpose is to add a random point inside each hole. In order to create the points inside the holes (...
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0answers
119 views

PyQGIS raster image shifted from vector shapefile

I previously asked a question about my raster image being larger and shifted over from my vector image here, but now I realize that the raster image is only shifted to the left and up from the vector ...
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0answers
17 views

Morphing Polygons using ArcMap? [duplicate]

We recently migrated from ArcMap 9.3 to 10.6.1. Since migrating we are experiencing issues with polygons changing after we hit finish sketch. This usually happens when there are curves or indents ...
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0answers
47 views

Changing the color and near ocean with QGIS

The border of region near ocean looks looks very fat. How can I change color of border lines near ocean to make it thicker? I want to change color and thikness of line only near oceans
2
votes
2answers
113 views

Editing border shape using QGIS?

I add a shapefile of the district in Paris on another shapefile. I would like to match them. See images below: The black border is the original, the blue one is what I want to get. I tried with the ...
2
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1answer
54 views

Dividing shapefile with many polygons into equal parts

I have a shapefile with hundreds of caribou movement corridors. using this data, I am trying to create a map displaying the frequency of use to determine important movement and migration pathways for ...
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0answers
65 views

How to select nan values in QGIS

I have a shapefile of a lot of polygons. I calculated perimeter of each polygon and some polygons returned nan values as they have hole/ring. I am looking for a way to select the polygons with 'nan' ...
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0answers
17 views

Rotate feature around defined fixed point using ArcGIS 10.4

I have a polygon feature and want to rotate it around defined (fixed point). There is a Rotate tool in Editor toolbar but I can't define fixed rotation point. I am using ArcGIS 10.4 and want to know ...
0
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0answers
43 views

Selecting polygons based on their shape

I have a polygon shapefile consisting of a lot of irregular shapes. I would like to select longer shape polygons like the one inside the red circle in the image. Is there any tool or algorithm which ...
13
votes
2answers
377 views

Transferring flows (connections + values) between polygons

In QGIS there are two shapefiles representing the moving data between cells and one additional layer, see image below Moving data defined by: Polygon "LayerA" (transparent squares with red outline)...
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1answer
34 views

Merge polygons based on nearest area

I have multiple polygons that show me metropolitan areas and rural areas across a state. I want to modify the layer so that there are no rural polygons by assigning portions of the rural polygons to ...
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0answers
50 views

How to preserve the Multiploygons using Python?

I converted my input file with geometry Polygon 25D to an output file with geometry Polygon using the below code. As you can see the below image. Problem is that the holes in the polygon is vanished ...
3
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3answers
129 views

How to remove narrow polygon dangles

Using QGIS v 3.4.4. I have a polygon layer in which some shapes have a very narrow extension that i would like to remove. Unless zoomed in these extensions appear as dangles but when zoomed right in ...
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0answers
40 views

Quadtree based polygon indexing? (Python/Java)

I was wondering how to best represent the inside of any given polygon (GeoJSON coordinates) with some sort of indexing, like a grid or quadtree? See image below for an approximation of what I have in ...
0
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1answer
27 views

Confusion regarding topojson Polygon coordinates

I have a topojson file which represents a hexagon. A hexagon has 6 vertices, so I was expecting the arcs attribute of topojson file would contain 6 points, but it contains 7. I wanted to know why ...