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

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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 ...
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2answers
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Intersect Shapefiles using Shapely

What I'd like to try and do is intersect some point buffers with census tracts, maintain their ID's and the tracts attributes. I found a sample from ...
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2answers
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Dissolve polygons based on attributes with Python (shapely - fiona)

I have been trying to create a function that does basically the same thing that the QGIS "dissolve" function. I thought it would be super easy but well apparently not. So from what I have gathered ...
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1answer
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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 ...
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2answers
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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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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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5answers
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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, ...
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1answer
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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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1answer
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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 ...
3
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1answer
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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 ...
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1answer
555 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 ...
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2answers
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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 ...
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2answers
911 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
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1answer
458 views

Shapely/ Python looping through a number of polygons

I am trying to loop through a set of polygons in shapely so using python) to determine whether they overlap or not. I do not want to do it manually as later i want to generalise the procedure and do ...
2
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1answer
95 views

How to find the intersection areas of overlapping buffer zones in single shapefile?

Find the intersections of the buffer zones I found an example where they tried finding the intersection of two different shapefiles -Intersect Shapefiles using Shapely. I've tried to adapt my code to ...
2
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2answers
837 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
519 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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1answer
795 views

How do I find out if a given lat lon is in a KML Linear ring using shapely?

I'm a GIS basic/novice user. I have some LinearRings in a KML file that give the areas for a bunch of different regions. And then I (will) have some lat lons that I want to test to see if they're ...
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2answers
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Python Efficiency — Need suggestions about how to use OGR and Shapely in more efficient way

I'm looking for some suggestions about how to make my python code more efficient. Normally efficiency doesn't matter for me but I am now working with a text file of US locations with over 1.5 million ...
11
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1answer
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Polygon overlay with Shapely

I'm trying to capture all the non-overlapping polygons indicated below using Shapely (given polygons A,B & C). Moreover, I'm hoping to do so without iteration, testing for intersect etc. The ...
4
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1answer
4k 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. ...
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2answers
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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 ...
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2answers
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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 = ...
4
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1answer
415 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 ...
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1answer
230 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: ...
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1answer
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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 ...
5
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2answers
189 views

intersecting two shapefiles from Python or command line

I'm new to working with geo data and trying to address a similar question to the one posted here. Using command line and/or shapely/fiona, in the most efficient and elegant way. I created two ...
7
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2answers
92 views

Polygons across international dateline [-180..+180 longitude]

I'm trying to generate polygons for satellite orbital swaths. So far I have a method to generate two lines which represent the edge of each swath in [lat,long]. Some of the swath's cross the ...
2
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3answers
106 views

I have an existing attribute table that I'd like to add values to the fields within it while preserving the geometry, how can I do this?

I've tried to use fiona and shapely and ogr, but the tutorials seem to be insufficient to describe how to do such a seemingly simple task. In arcpy this could be done simply with an update cursor. ...
2
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2answers
747 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 ...
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1answer
37 views

How to find the area with most intersection for buffer regions?

Find the area with the most intersection This question relates to previous question asked - How to find the intersection areas of overlapping buffer zones in single shapefile?. I tried to ...
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1answer
120 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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1answer
612 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, ...
0
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1answer
23 views

How can I add points to a LineString in shapely?

I have two Polygons which intersect along one edge as shown below. I need to add the red vertices at each end of the intersection to the blue polygon. I thought I could do this with by calling ...
0
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2answers
203 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 ...
0
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2answers
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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 ...
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1answer
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Shapely LineString and Polygon intersect?

here is my python code, it does not intersect and when I plot this in google map , I see the intersection. shapely.geometry is in Cartesian plane, how you are solving this? l = "40.65:-114.07 ...