5
votes
2answers
226 views

Is there a way to calculate closest distances to a point without using Near Analysis?

I frequently get asked to calculate distances from a specific point (A drilling well in the middle of the sea for example) to a number of Environmental layers (Protected Areas, Pipelines, Other wells ...
1
vote
2answers
112 views

Calculating distances between points two feature datasets

I will do my best to explain my problem. I have two feature datasets. One set has about 100 points that are "city centers." The other dataset has points for each census tract in each of these 100 ...
3
votes
2answers
561 views

What's the difference between vincenty and great circle distance calculations?

Python's geopy package features two distance measurements techniques: Great Circle and Vincenty's formulae. >>> from geopy.distance import great_circle >>> from geopy.distance ...
0
votes
0answers
96 views

Calculating distances between boundaries of polygons with Python

I have two sets of shape-files which have to be worked on within a Python Script. Those two Shape Files might differ from each other (same thematic content, but 2 different epochs). If there occurred ...
0
votes
1answer
143 views

Manipulating distances in python. Problem with ShapeLength

I have a question more than a problem. I'm getting the distance of a line using python with arcpy.da.SearchCursor or FeatureClassToNumPyArray. The result I get is a double. Example: ...
0
votes
2answers
373 views

Find longitude for point between two coordinates with pyproj?

I've written a function to get the longitude of a point of known latitude between two known points (might not be working correctly yet), but I feel like there must be a better way of using pyproj to ...
5
votes
1answer
1k views

Shortest distance from point to line (big dataset)

What is the best method to calculate the distance from the nearest road for a series of address points in QGIS, having a very big dataset? (QGIS 2.0.1, Win XP) I read the answers to previous similar ...
5
votes
2answers
306 views

How to create a point along a line given a distance from another point

I'm trying to figure out a point(D) on B-C that is a specific distance from A. I really don't have any idea on how to proceed with the ellipsoidal math so I figured I'd ask here. How would I figure ...
4
votes
1answer
382 views

How to access the road graph plugin in python?

I am developing a few scripts in Python for QGIS 1.8 to automate some geo-tasks and one of them would be to calculate the shortest distance from a hospital to each building in a town. I would like to ...
3
votes
1answer
136 views

Get the total distance from a point to the end of a linestring

I have a list of GPS coordinates that make up a bus route: busRoute = [(x1, y1), (x2, y2), ... (xn, yn)] I also have a point that may not be exactly on that route (due to GPS error): ...
1
vote
0answers
334 views

Get the distance between 2 WGS84 GEOSGeometries

I currently want to check if 2 given GEOSGeometry objects of type Point are within 100m of each other. (length flexible) Looking at previous asked questions on this topic, most of the answers were ...
2
votes
3answers
1k views

How to measure minimum distance between objects in two layers using arcpy?

I am working on an alien species analysis looking at the spread of a species from the mainland to islands in an archipelago. I am doing the analysis using arcpy and I have succeeded in isolating risk ...
6
votes
3answers
4k views

Splitting lines automatically at specific distances using ArcGIS Desktop?

I have a set of polylines which I need to split at varying distances from their starting points. In general, I'm looking for a something similar to the SPLIT function within the editor tool. There ...
1
vote
1answer
905 views

Radius of Curvature Python/Arc, how access x,y coordinates

I have a polyline in ArcMap 10 and I am able to script the length of the line in Python using this bit of code: #Calculate Radius of Curvature #try: # Import system modules import sys, string, os, ...
2
votes
1answer
1k views

Using a geodjango PointField with geography=True, my distance calculations are wrong

Here's my model: class ExchangeArea(models.Model): """ An Exchange Service Area, calculated from a phone exchange and surrounding census tracts. """ coordinates = ...
9
votes
2answers
2k views

Measuring distance in spherical Mercator vs zoned UTM

I've got points in WGS84 lat/long and I'd like to measure "small" (less than say 5km) distances between them. I can use the haversine formula from http://www.movable-type.co.uk/scripts/latlong.html ...
12
votes
6answers
4k views

What tools in Python are available for doing great circle distance + line creation?

I need to use Python to create a great circle distance -- both a number, and preferably some kind of 'curve' that I can use to draw in a client-side map. I don't care about the format of the curve -- ...