Shapely is a BSD-licensed Python package for manipulation and analysis of planar geometric objects.

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1answer
93 views

When validating geometries, what are “Nested shells”?

I am validating shapefiles polygon geometry using shapely, and have also attempted it using FME. Some polygons return the error "Nested Shells". I cannot find a definition of what the problem is, ...
1
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0answers
88 views

Error and kernel dies with shapely/geos inside Jupyter notebook

I have a Python 2.7 script (code below) that scrapes data from a table on the web and draws a map. It runs fine from the command line using $ python bears.py When I run the identical script from ...
1
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1answer
95 views

How to split epsg 4326 linestring in parts consisting of given length in meters in python?

I want to know linestrings (epsg:4326) length in meters instead of degrees. I know that I can use proj4 for that. Here is my code, if you interested. project = partial( pyproj.transform, ...
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0answers
63 views

Creating spatial layer from MS SQL Server table?

I have a table in MSSQL that I am trying to use to create a spatial layer from using the QgsVectorLayer function to load the table as a layer, and then using Fiona to create a shapefile but I am ...
-1
votes
1answer
93 views

fiona writing geometry into shapefile problem [closed]

Context: I use lxml library that generates some dictionary (infact it is xml attribute dictionary) from xml and i am trying to write these into a shapefile-i.e. get one element-attribute from xml ...
4
votes
2answers
963 views

Reading postgis geometry with shapely

I am doing a small-scale workflow in ipython notebook with geopandas and shapely, pulling a bunch of geospatial data, sometimes from shapefiles, sometimes from postgis (where more expensive processing ...
5
votes
2answers
1k views

Transforming Shapely Polygon and MultiPolygon objects

Is there an easy way of transforming Shapely objects (namely, Polygons and MultiPolygons) from one projection to another without having to dig around and extract coordinates by hand? In fact, I don'...
2
votes
2answers
904 views

Maximizing Code Performance for Shapely

I've written this code in order to calculate the percent cover of grassland within a national park, within 20km^2 of points of recorded occurrences for a species. It is designed to only consider the ...
3
votes
1answer
156 views

What is Shapely library alternative in R?

I want to manipulate 2D geospatial geometries in R. I am used to using Shapely in Python but I am a newbie in R. Can you suggest Shapely alternatives for R?
4
votes
2answers
412 views

geopandas/shapely: what units it uses/calculates for area and distance functions?

it looks like a silly question, yet I can't find clear answer on that: what units geopandas/shapely use calculating distance/area between objects?
1
vote
1answer
510 views

GeoPandas: return lat and long of a centroid point

I would like to return the lat and lon or x and y from the point object in the following series as I plan to link them with an API I built that links OSM and NetworkX. The centroids will be added as ...
0
votes
2answers
239 views

Python buffer points and clip with line-segment (OS Open Roads in BNG) [duplicate]

I have an array of points (in latitude, longitude coordinates) which I would like to buffer and dissolve (into a polygon) and then intersect the Ordnance Survey Open Roads (projected in BNG) with that ...
5
votes
0answers
157 views

Counting features into intersections of Shapely Polygons

I have a geopandas GeoDataFrame containing hundreds of shapely Polygon and MultiPolygon geometries. The polygons overlap in lots of places. I'd like to make a new geometry that contains a count of how ...
2
votes
2answers
71 views

How to successfully do “nested” looping over a Fiona collection

I wrote some code that basically loops over all features in a shapefile with Fiona in Python, doing some things, calculating some things, etc. I found that it would exit the for loop prematurely, ...
3
votes
1answer
212 views

QGIS Contour Plugin Says No Shapely; can import shapely in QGIS console

I'm keen to create some contours (isochrones for a pedestrian 'ped-shed' catchment) from a point dataset in QGIS, using the contour plugin from the Plugins repository. I installed the plugin, but ...
1
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0answers
29 views

Shapely's object.project method dealing with overlapping polyline

So I am interested in knowing how far along a polyline a given point sits. Python's shapely package has a method to do such a thing, see the below code: from shapely.geometry import LineString ip = ...
0
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0answers
41 views

Understanding output point in polygon solution?

My question refers to an old solution which is provided in How do I find out if a given lat lon is in a KML Linear ring using shapely? Using python3 I needed to update the code somewhat to get this ...
0
votes
0answers
34 views

Finding common segments in Shapely LineStrings

I have two identically-sized collections of Shapely LineStrings, representing two sets of routes from a common origin to a set of common destinations. For each "pair" of routes (i.e. set_a[0], set_b[0]...
1
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1answer
73 views

Valid shapely dumps WKT becomes None when used as input to QgsGeometry

I'm trying to produce a multipolygon feature in QGIS. I am producing filled contours with Matplotlib, taking the multipolygons representing each contour level, using shapely to produce WKT, and then ...
1
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1answer
181 views

how install shapely on windows so it can be imported from matlab?

i'm on windows 7/64. shapely doesn't offer windows installers on their pypi page, even though they seem to have recently (github issues 104 and 109 -- i don't have the rep to post links. their pypi ...
1
vote
1answer
126 views

Country border between two points

I am trying to extract country borders between two points, using Python. The border is a Shapely Polygon.exterior or LinearRing, the start and end points are Shapely Points. My idea is the following: ...
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0answers
436 views

Point in Polygon using Rtree and Shapely

This is a repeat of my question over on StackOverflow. All, I am wondering what the correct syntax is for doing a point in polygon search using Shapely and RTree. I'm really interested in speeding ...
5
votes
2answers
1k views

Understanding the Use of Spatial Indexes

I'm having trouble understanding the use of spatial indexes with RTree. Example: I have 300 buffered points, and I need to know each buffer's intersection area with a polygon shapefile. The polygon ...
3
votes
2answers
851 views

create polygon adjacency matrix using python

I am trying to create an adjacency matrix from a set of polygons. That is, I have a bunch of polygons and I want to identify which polygons have a common edge or "touch" each other. Once I find this ...
2
votes
1answer
787 views

Plot points on map using Fiona and/or Shapely

I have written a parser in Python that extracts the coordinates out of a GPX file and I would like to view those points on a map. I have done a little research and it seems like either Fiona or ...
1
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1answer
320 views

differences in distance between shapely and geopy

I am getting totally different distances from shapely and geopy. On one hand - it makes total sense, shapely measures on a plane and geopy measures on a spheroid. But the differences are so dramatic, ...
2
votes
1answer
138 views

Why is Shapely and contains_point not detecting point being on land?

I'm using the world shape file that can be found at https://trac.openstreetmap.org/browser/applications/editors/merkaartor-branches/merkaartor-0.14-fixes/share/world_shp/world_adm0.shp?rev=17052. I'...
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0answers
123 views

Reading/writing utf-8 encoded data using Fiona?

So I have a 'cpg' file with my 'in_file' shapefile data (definitely set to 'utf-8'). I was using 'meta' to create the same schema/crs as 'in_file'...though it runs, my text fields are borked on ...
1
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1answer
450 views

Problems with Geometry collections. (Fiona: write output of Multipoints and Points)

Updated: I am getting the following error on this function: ValueError: Record's geometry type does not match collection schema's geometry type: 'Point' != 'MultiPoint' The problem is that I have ...
0
votes
2answers
876 views

How to measure distance using shapely

Reading the documentation...it looks like I should have this right, but I don't. The example is: Point(0,0).distance(Point(1,1)) 1.4142135623730951 Based on this example I wrote this block ...
1
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1answer
130 views

How to call 'shapely' .coords on a fiona filtered list?

I have to filter a shapefile by attribute then compare it to another shapefile using .coords...however I am a bit perplexed how to do this as my filter is returning a list type...(and .coords requires ...
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2answers
166 views

Shapely (geos) crashes during unary_union

When attempting to union multiple polygons with Shapely 1.5.6 in Python 2.7.9, using GEOS 3.4.2, I get the following error in the underlying C++ code: Assertion failed: (!"should never be reached"), ...
2
votes
1answer
107 views

How to find the distance of a point from the begning of a StringLine with shapely?

I have a route (represented by StringLine) and a location (Point) and I need to find the progress of the location in the route. The progress is the distance in meters from the begning of the route. ...
2
votes
1answer
172 views

Error with Python Script using Shapely

My professor gave us a basic Python script that demonstrated how Shapely works with a shapefile, however it's not working for me. Here is the code: from shapely.geometry import mapping, shape from ...
5
votes
2answers
5k views

GEOS and Shapely installation on Windows

When trying to install Shapely on my Windows 64bit computer, I cannot get the GEOS library to work. So far, I have run the OSGeo4W installer from which I installed GDAL (I believe the geos library ...
6
votes
5answers
2k views

Python, shapely library: is it possible to do an affine operation on shape polygon?

I am trying to create a rotated rectangle in lat/lon coordinates. Basically, I have the coordinates of the center and rotation angle around the center. Is it possible to do using, shapely or gdal, ...
1
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1answer
619 views

Writing a shapefile using OGR, from Shapely Geometry - No feature added Error

I am trying to write a shapefile from a Shapely geometry using PyQGIS in the QGIS 2.6.0 console. Lines of code before the OGR method to write shapefile: extnt = poly.extent() # gives a QtRectangle ...
1
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1answer
343 views

Multi-part Geometrical Intersection error

I am working with intersection of polygon and line segments (continued from a previous question). When a Line intersects with a Polygon, the result is a LineString; When a LineRing intersects with ...
3
votes
1answer
490 views

How to get the two nearest points between two polygons

I'm trying to draw the nearest line between the nearest polygons in a Polygon dataset (ESRI Shapefile). I know that for this purpose there is the Near Tool (ArcGIS), but it just return the point TO ...
6
votes
1answer
1k views

Line vs. Polygon Intersection Coordinates

I am working with Python, Shapely and Fiona... Is there any way where I can give in an input of a line shapefile and a polygon shapefile, and get a result of the intersection points and their ...
1
vote
1answer
240 views

Fastest way to add shapely geometries to a PostGis database using geoalchemy2

I am looking for the absolute fastest approach to adding +10,000 shapely geometry objects to a PostGIS database using geoalchemy2. I'm having no speed issues when uploading to a localhost postgres ...
0
votes
1answer
921 views

Installing Shapely with libgeos_c on Linux?

The installation instructions for shapely suggest: "Windows users should use the executable installer, which contains the required GEOS DLL. Other users should acquire libgeos_c by any means, make ...
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0answers
576 views

Generate random points in polygon. Algorithm question

i created a Random Point Generator in python using the algorithm described here by @whuber. The algorithm is implemented using Shapely, PostGIS and psycopg2. To boost performance pythons ...
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votes
2answers
1k views

How do I import geos from shapely? [closed]

I clearly have geos installed under shapely, since I downloaded "Shapely-1.4.4.tar.gz". Also, the result can be seen in my directory in the correct path: C:\Python27\Lib\site-packages\shapely\geos....
0
votes
1answer
578 views

creating circle with radius in metres

I am using shapely and python. How should I go about creating a circle using shapely whose radius is in meters? If i use sampleCircle = Point(1,1).buffer(1) print sampleCircle.area This returns an ...
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2answers
3k views

Convert shapely polygon coordinates

I am trying to work with a shapefile using shapely, fiona and python. The original coordinate system is in latitude and longitude that I am trying to convert to state plane system. So I want an ...
3
votes
3answers
576 views

Removing small polygons gaps in a Shapely polygon

I know this issue has been addressed before with different software, but I am looking for an approach with Shapely. I have a polygon with a very small gap on the interior of the shape: Here is a ...
0
votes
2answers
745 views

problems with py2exe, shapely and fiona

I have a short python script, called test: import fiona with fiona.open("C:\\Essai_compil", 'r') as l_Obs_shp: for shp in l_Obs_shp: print shp['geometry'] I want to compile with ...
2
votes
1answer
326 views

Shapely's simplify won't simplify any more

I have a multipolygon in shapely, and I want to simplify it until it has less than a certain number of points. When I use the preseve_topology=False argument to geom.simplify, I can get the number of ...
1
vote
1answer
145 views

Properly writing floats to feature properties of a new shapefile in Fiona

The following piece of code returns a shp following the driver and crs of a model .shp. import numpy as np #just to test I correctly handle data types import fiona from shapely.geometry import ...