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

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MultiLineString to separate individual lines using Python with GDAL/OGR, Fiona, Shapely

There are lots of MultiLineString features in a polyline shapefile. The problem is to split these lines into separate individual lines. There is a similar question with PostGIS, but I need to code in ...
3
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2answers
214 views

Can I convert the sharp edges of a polygon easily to round edges?

I use the python module "shapely" to make Polygons (like below). Can I convert the sharp edges of a polygon easily to round edges? Such that when I have unified some polygons I could issue a command ...
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1answer
85 views

Add attributes to an output shapefile schema (via meta)

I am trying to copy the schema of an existing shapefile and add to it in an output shapefile. Somehow I am not getting anywhere with this...though the docs seem very clear (and the download page : ...
3
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1answer
989 views

Converting Matplotlib contour objects to Shapely objects

I would like to convert a Matplotlib contour collection to a Shapely geometry collection, in order to calculate the area contained within closed contour lines. it seems that all the information is ...
2
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2answers
696 views

How to create a Shapely LineString from two Points

If have two points, from which I want to create a straight LineString object: from shapely.geometry import Point, LineString A = Point(0,0) B = Point(1,1) The Shapely manual for LineString states: ...
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3answers
428 views

Install Shapely with GEOS on heroku

I have a web mapping app running on Heroku. My app is written in python. Using pip I was able to install various pure python libraries that were needed. I would now like to install Shapely too. ...
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0answers
56 views

Point in Polygon operation for 100G of data

I have lat/lon point locations for over a billion points, all based in the US. For each point I would like to generate a dataset that links them to their county and to their MSA according to US Census ...
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1answer
194 views

Shapely WKT precision/rounding

I'm using Shapely's wkt.dumps function to get WKT from geometry objects. I can't seem to find a way to limit the precision of the coordinates. Any help is appreciated.
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0answers
101 views

need help creating layer with geom type wkbGeometryCollection with gdal python

I am having trouble creating a layer with geom type as geometry collection. Thus I am unable to output to a shapefile. I have attached code below. dstLayer is null. This does not happen if geom type ...
7
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1answer
674 views

Is there a significantly faster way to buffer than arcmap? [duplicate]

I hope this question is appropriate here and I apologize if it is more of a discussion question than a specific technical problem. I have to buffer 150,000 polygons for a real estate project. While ...
8
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1answer
509 views

How to split two interscting polygons by the average linestring of the shared area (QGIS / python shapely)

I have two polygons, POLYGON((-5 -5,-5 5,5 5,5 -5,-5 -5)) POLYGON((1 1, 1 7, 7 7, 7 1, 1 1)) and wish to split them evenly. The result should be a split along the red marked line. I'm using ...
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1answer
369 views

Equivalent function to shapely's envelope in ogr?

I wrote a very simple python function that gives me the envelope/bounding box/...based on two coordinate pairs (ower left and upper right corner): # ... def get_bounding_box(self, ll_corner, ...
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2answers
2k views

Creating Shapely MultiPolygons from shape file MultiPolygons

I'm reading a shapefile using Fiona: with fiona.open('data/boroughs/boroughs_n.shp') as source: mpolys = [p for p in source] candidate = polys[0]['geometry'] this gives me a dict containing a ...
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3answers
6k views

How to write Shapely geometries to shapefiles?

Can someone demonstrate a simple way to write geometry data-structures from shapely into shapefiles? I am particularly interested in polygons with holes and linestrings. It would also be beneficial to ...
5
votes
2answers
863 views

how would one get the end points of a polyline?

I am attempting to write a script to get the end points of a series polylines, and then use those end points to create a polygon. I'm not sure which tools to begin to use on this project. I would ...
3
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2answers
1k views

How to install shapely for python 2.6 (Mac) NOT 2.7?

I'm trying to use Polygonizer plugin inside QGIS, but it needs Shapely to work. I've installed Shapely (pip install Shapely) but that's for python 2.7. QGIS works with python 2.6 (on Snow Leopard) and ...
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2answers
634 views

Get the vertices on a LineString either side of a Point

I have a shapely LineString and defined a shapely Point which lies along the LineString. How can I find the vertices of the LineString which lie either side of the point? (split the line in two). ...
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1answer
215 views

create a pie shaped object in shapely and export to gis polygon object

I would like to create a pie chart-shaped polygon with concentric layers like so: I can create this simple object with: from math import sin, cos, radians from shapely.geometry import ...
4
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1answer
2k views

Shapely unable to tell if polygon contains point

For an application I want to determine under which constituency a given coordinate falls. After looking at the various options, I decided upon shapely and fiona as the easiest way to implement this. ...
2
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2answers
570 views

Shapely MultiPolygon Construction - Will not accept the entire set of Polygons

I am new to Shapely, so I am using a work request to learn a bit more about it. I need to execute a number of unions to build larger geometries from assessment neighborhoods in DC. I am curious ...
3
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1answer
379 views

Serialize python list containing geometry

In simple case if list doesn't contains geometry all works fine: result = [dict(f.fields, id=f.id, label=f.label) for f in features] json.dumps(result) But if result list contains geometry ...
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1answer
145 views

Shapely Python NameError when using cascaded_union

I am fairly new to Python and therefore my error-solving skills are not much yet developed. I am using Python within a geoprocessing script which is supposed to use ogr (reading/writing shp) and ...
7
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1answer
1k views

Find Nearest Line Segments to Point

Background From a known Point, I require to establish the nearest surrounding "visible perimeter" against a table of MultiLineStrings, as shown on the diagram. I've searched this site with a number ...
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2answers
1k views

What is the unit the shapely length attribute?

I'm doing a very simple calculation of the length of a polyline using shapely: from shapely.geometry import LineString ... xy_list = [map(float,e) for e in xy_intm] line = LineString(xy_list) s = ...
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1answer
616 views

Finding differences between two shapefiles in Python

I'm trying to find out whether there were any border changes between two yearly shapefiles. I've heard a lot of praise for Python's open source GIS tools like Shapely/Fiona, and thought I would try ...
3
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2answers
3k views

Determine if point is within an irregular polygon using Python

I would like to create a mask of a grid where points are evaluated as either 1's or 0's depending on if they lay outside of an irregular (i.e. not rectangular) polygon. I have a set of high-latitude ...
5
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1answer
836 views

Wrap GEOS functionality into python

I've been looking on how to get GEOSExtractLine available in python. I looked into Shapely source to if it was available for it, but it's not. I'm trying to wrap this funcionality into Django, much ...
3
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1answer
635 views

Fiona - Preffered method for defining a schema

I'm fairly new to the world of python and GIS - so this is definitely a beginner question. I am following Tom Macwrights small guide to Shapely and Fiona, and I noticed that even when opening the ...
2
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2answers
508 views

Does shapely within function identify inner holes?

I have a series of shapefiles that include both polygons and multipolygons. I am using ogr to extract them in wkb, and them I am using shapely to check if a point fall inside a polygon (or a ...
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0answers
138 views

How to shift vertices of shapes in shapefile using FOSS python library?

I need to shift each vertice of shape in a shapefile (of any type:point, line, polygon, multiline etc.) with Python. I need to loop in all shapes, get the vertices, get it's coordinates and for each ...
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2answers
566 views

Convert 3D WKT to 2D Shapely Geometry

I have the WKT of many linestrings which contains three dimensions, however my script only requires a two dimensional linestring and I therefore want to discard the third dimension. My current code, ...
4
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1answer
286 views

How to generate overlapping polygons from lines output from Table To Ellipse tool?

I have a feature class of line-based ellipses generated by the Table to Ellipse tool that looks like this: What I want is polygons of the individual ellipses, however tools like Feature to Polygon ...
5
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4answers
640 views

How to computational efficiently check if there are any overlapping polygons in a group of polygons?

I need to do some processing with groups of polygons. If any of the polygons in the group overlaps other polygon the result is unpredictable and don't throw any error. So, I need to detect if there is ...
2
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1answer
2k views

How to install shapely on Ubuntu 12.10

I have tried to install shapely on Ubuntu 12.10. Therefore I installed libgeos-c1, pip and shapely with $ pip install Shapely. The shapely files are now in /home/user/build/Shapely. When I try to ...
3
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1answer
306 views

Is there an online reference available for the Fiona and Shapely libraries?

Is there an online reference available for the Fiona and Shapely libraries? I'm thinking a real reference, beside the tutorial-style documentation: http://toblerity.github.io/shapely/manual.html ...
2
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1answer
68 views

how to differentiate between common parts of the triangle and extract linestring from it

Can you help me break down shape A to different linestrings: lines 2 & 3 AND line 1? The shape contains three different polygons (A, B, C). I wish to determine the start/end point of each part ...
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0answers
378 views

Install shapely for QGIS on Mac

I know there are a number of similar questions, but none of them have answers that allow me to use shapely in QGIS. In particular I am trying to install the Contour plugin, but this fails with the ...
5
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2answers
953 views

Why is Shapely not installing correctly?

I am trying to run Shapely on a new machine, and tried both installing it from source, using the installer on its webpage, and using pip install shapely. Every reference I try to make from the library ...
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2answers
898 views

How to install Shapely, but got stuck into Python language

I have a MAC OSX 10.7.5 and am trying to learn how to use QGIS. Following a couple of tutorials I came to know I have to install shapely. I followed the instructions by the multi-cited ...
5
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2answers
1k views

Python: How to export Shapely objects to DXF file

Using shapely package for Python how to export the resulting shapely objects such as buffer to a DXF file?
7
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2answers
2k views

Converting KML files for use with Python library Shapely

I am trying to get a KML-file (wijken.kml) into Shapely. The KML-file is validated against the proper XML schema, so I guess the input is correct. Routes I have tried: 1) Converting to WKT or WKB ...
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0answers
231 views

Why does polygon.intersection(complex_linestring) split the linestring and mess up Z?

I have a complex (self crossing) line with Z values which I'd like to truncate to the area inside a box. The problem is Shapely splits the line into simple (non-crossing) sections and the Z value at ...
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1answer
207 views

How to set the path to shapely?

I am using QGIS 1.8.0 on Mac OS 10.8.3 with python 2.7. Thanks to other threads in the forum, I have successfully installed shapely here: ...
9
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4answers
7k views

using shapely: translating between Polygons and MultiPolygons

[EDIT: the solution to this was simply to use OGR to read shapefiles. See geographika's example.] In an ESRI shapefile, there is no distinction between Polygons and MultiPolygons. Furthermore, there ...
2
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1answer
2k views

QGIS Python version

I have brewed python 2.7.3 onto my Mac (Lion), and installed shapely via pip install shapely. The Polygonizer plugin, however, does not find the shapely library. I see when QGIS loads a Python ...
3
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0answers
395 views

Importing matplotlib basemap and shapely

I'm not sure if this is the right place to ask this, but here we go. I have a python script that uses matplotlib's basemap and another part that uses shapely to do an intersection of 2 polygons. If ...
3
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1answer
947 views

Does anyone have a shapely install for python “dummies” guide?

I have read both questions in regard to installing shapely on a Mac (OS Mountain Lion) and haven't been able to figure it out. I'm not familiar with python syntax and am just trying to get shapely ...
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2answers
756 views

Python module “shapely.wkb” missing

I am trying to follow a tutorial from here http://qgistips.spatialthoughts.com/2012/12/find-neighbor-polygons-in-layer-in-qgis.html#more I have downloaded the relevant python script and edited it as ...
3
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2answers
815 views

Checking if a point is in a circle

I'm using shapely to check if a point is in a polygon, but I also need to check if a point is in a circle. Checking the docs, I don't see how do that... Maybe I could create a circle? circle = ...
5
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1answer
448 views

How do you fix Overlapping Lines?

I have a line dataset that contains some lines where the "end points" are actually found in the middle of the line. In the image below, the nodes are shown in green and one of the end points in red. ...