The measure of separation between two entities or locations that may or may not be connected, such as two points.

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129 views

How to convert distance in meters(EPSG:28406) to EPSG:900913 with OpenLayers?

For point I use OpenLayers and transform(): numZona = Math.ceil(parseFloat(lon)/6)); Proj4js.defs["EPSG:28406"] = '+proj=tmerc +lat_0=0 +lon_0='(parseInt(numZona)*6-3)+' +k=1.000000 ...
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26 views

Calculating offset distances perpendicular to parallel lines in shapeile with results written to table using ArcGIS for Desktop?

I have a line shapefile with sets of parallel lines (or sticks on the map) representing the map view of horizontal gas wells that were drilled. I'm looking for tool or Python script to measure the ...
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0answers
57 views

Why Haversine formula and Web Mercator give different length between two latlng points?

I am calculating the distance between two points given by latlng. However, Google Maps (i.e., web mercator projection) gives me a longer distance than Haversine formula. Which is the most accurate ...
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6answers
5k views

Which tools and methods can be used to create isochrones?

I'd like to get an idea for what's involved in creating isochrones for a series of sites, with a reasonable degree of accuracy to the estimates. A general outline would be great, though my scenario ...
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3answers
463 views

Draw line between points from multiple datasets

I have 2 point datasets and want a tool or script to draw a line between all points in one dataset to all the points in the 2nd dataset. Is it possible? I have tried ESRI "Point Distance" and ...
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2answers
2k 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 ...
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1answer
44 views

How to compute distances between points and polygon borders?

I have point data and polygon in vector format. For each point, I want the distance from the point to the border of the polygon. However, if the point is inside the polygon, I want negative distance ...
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269 views

How to calculate distance between point feature to multiple polyline features in ArcGIS

I have a GPS track which is basically a point layer. I have different route networks such as - train, tram and bus routes. I want to calculate the distance between each point to nearest features ...
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1answer
46 views

How to calculate the distance to the nearest coastline from site locations?

I want to calculate the distance to the nearest coastline from my site locations (point shapefile), and possibly the max distance as well. I am using ArcGIS 10.2 and I already have a shapefile of the ...
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0answers
32 views

Distance Measure appears to be wrong in ArcGIS Desktop?

The distances in my shapefile are completely wrong. I got this shapefile online. Does anyone knows what's going on? I attached two pictures. The shapefile is projected as ...
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1answer
760 views

How to calculate driving distance/time between two points

I am doing some analysis for our fire rescue department where we are comparing actual response times to fires vs predicted response times. The actual response time analysis is straight forward as I ...
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24 views

Calculating driving distances from a number of post codes to a number of services using QGIS

I am hoping to calculate the driving distance from a large number of post codes to their nearest service. I have used the RoadGraph plugin but this only calculates the distance and time from one ...
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1answer
34 views

Distance between point layers [closed]

I have a point layer with geographic boundaries of an area and another point layer with road network. I want to calculate the distance of each point of road network layer to the points of the ...
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1answer
131 views

Calculating distance between borders when one polygon inside another polygon?

I am brand new to ArcGIS and having some trouble. I would like to calculate the distances between the border of one polygon to another polygon. However, these polygons overlap. Thus when I use the ...
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1answer
58 views

How to delimit point distances in ArcGIS for Desktop per thiessen polgyon

I have 2 shapefiles. The first set contains xy pair for 1100 hospital locations. The second pair contains xy of villages about 7000 that are served by the hospitals. This means each hospital serves ...
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1answer
154 views

How to set the length of a line using openlayers

I'm trying edit a polygon by changing the length of some lines by code. Found this method to calculate based on the bearing. But I didn't find anything on how to calculate the bearing, before I start ...
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2answers
591 views

clustering points in postgresql to create contour map

UPDATE: To try to make this a little more simple, is it possible to create a query which selects a group of points such that each point in the group is at most X units away from at least one other ...
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0answers
20 views

distance() function in field calculator gives unexpected results

I have two layers both containing points - each point in the first layer has a corresponding point in the second layer (same primary key). One layer has CRS EPSG:27700 and the other layer has ...
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1answer
370 views

How to calculate the distance to multiple locations from each cell of my raster?

I'm working with Arcgis 10.1 and Python 2.7.2 How can I calculate the distance to multiple locations from each cell of my raster? I tried euclidean distance but it only provides the distance to ...
5
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1answer
816 views

Calculating distance in WGS84 (MySQL and Geoserver)

Here is the environment in which I work: An application using geo-referenced data Database MySQL 5.5, storing georeferenced points A Geoserver server, connected to the MySQL database Here is the ...
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1answer
47 views

Buffering line in ArcMap is creating smaller buffer than expected?

When I buffer a point (red dot on image) by 3 miles, it is 3 miles on all sides. When I buffer a line (blue line on image) by 3 miles, it is more like 2.67 miles on the sides parallel to the line. I ...
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1answer
110 views

Find nearby cities by a driving distance radius

I'm studying GIS services to solve one specific need: Given x/y coordinates of one city, I want a JSON result that lists only cities (not facilities) that are nearby the specified city, within a ...
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3answers
130 views

How to convert points to lines?

I want to convert these points to lines, however they are not sorted sequentially along a line (by ID or FID), i.e. the converted lines zig-zag across the obvious trail of points. How can I join ...
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2answers
2k views

Calculate Distance between a Polygon and a Point Along a Path

I am very new to ArcGis and am trying to figure out how to do this. Basically, this is what I am trying to do: I have a map of Canada and in it I have polygons representing areas (each about the ...
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1answer
51 views

Distance of points to nearest polygon edge in ArcGIS 10.2

I have a point feature class that consists of a systematic grid of points across a landscape. I also have a shapefile consisting of several polygons. For each point in the feature class, I'd like to ...
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3answers
54 views

Using GDAL/C++ to calculate distance in meters

I'm using GDAL in C++, with WGS84. I want to calculate distance between two points in meters. The code snippet below tries to find the distance between 25N/75E and 25N/76E. The code, as is, returns ...
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1answer
249 views

How to calculate which zip code is closer to which in USA using C#?

I'm not living in USA, and I'm doing a small project for a company based in USA. The point is that, there are businesses and each of them have their address and zip code. Then, I have a form where ...
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22 views

Generate Near Table (path distance)

I have a number of points and want to get path distance to all "wetland" polygons within 1km. This is very easy with eucDistance in Generate near table, is there a was to alter this to give path ...
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16 views

QGIS modal value within distance

I have a vector layer with several values associated to each polygon. I then have a point vector layer. I want to get the mode of each value for polygons within 500 km of each point. I'm not sure how ...
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2answers
411 views

Measure average distance between two lines with common endpoints

I have two shapefiles, each with a set of lines generated from start and end points. One shapefile has the straight lines generated from the XY To Line tool, while the other has lines generated from a ...
4
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1answer
442 views

How can I make a Postgres/PostGIS ST_Distance_sphere query more efficient?

Within Postgres/PostGIS I have written an SQL query to get the closest distance for each element within a point coordinate table from a polyline table. The query comes back and works correctly, but ...
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0answers
18 views

Distance corresponding to fractions of a minute of lat/long [duplicate]

My GPS is set to degrees minutes fractions of a minute. I am trying to determine the distance represented by a single increment on the Lat and Long of fractions of a minute. IE. traveling from ...
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1answer
16 views

polygon vertex to vertex distance calculation in arcobjects

I have polygon with multipart (donuts) I want to calculate vertex to vertex distance. I tried to get outer ring vertex to vertex distance and it is working. Could you please tell me how to get inner ...
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2answers
51 views

Create buffer along shoreline near sample site

I want to look at the land use on the shoreline of a river relative to a specifc point on the river. I have created a point on the shoreline using the Near tool. Following this I am having trouble. I ...
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2answers
91 views

Calculating average raster to point distances within census tracts

I have some experience using ArcGIS, but mostly with the field calculator in the attribute table/spatial joins, so I apologize if I say something that doesn't make sense. To provide a bit of ...
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0answers
75 views

Merging rasters which overlap using ArcGIS for Desktop?

I need to merge two rasters which overlap, both indicate distance values. I need the output of the merge to result in the shorter/lower distance value. I am using ArcGIS 10.1. I hope it is more ...
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0answers
36 views

How to create an attribute table from a Euclidean Distance Raster?

I am trying to create an attribute table from an Euclidean Distance Raster. I get the following error: "error 000423: Only single band integer dataset is a valid input". The ED Raster has actually the ...
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1answer
29 views

Distance to object, taking into account size of object

I have a number of polygon features on the edge of a lake feature. I also have sample points throughout the lake feature. I am looking to add some sort of indicator for these points as to how ...
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1answer
32 views

SQLite db with FDO geometries: how to assign ID of point in layer A to closest point in Layer B with SpatiaLite?

How can I assign ID of point in layer A to closest point in Layer B with SpatiaLite (find nearest neighbors for each point in A)? For each point stored in table fdo_fc1 I would like to select one, ...
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1answer
51 views

How do I generate a distance table using 2 different point files and a line file?

I have two point datasets, one containing multiple transit stops and the other containing multiple schools. I also have a street line dataset. I need to generate a table that gives me the shortest ...
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1answer
51 views

Postgis ST_Distance query returning inaccurate results

I am using the following query to retrieve records from a postgresql DB @services = Service.select("*, ST_Distance(services.lon_lat, ST_GeomFromText('POINT (lat lon)', 4326)) as ...
3
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1answer
81 views

Proof of part of haversine formula?

I'm trying to study how to find the distance between two points if their latitudes and longitudes are given. I have a question about the proof of part of the haversine formula given at Math Forum. ...
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1answer
4k views

How to find nearest point for each point in current layer using ArcGIS Desktop?

I have a point layer and want to know the distance of nearest point of current layer for each point in the layer. I found some tools in ArcToolbox about it , but they need two layers for input and ...
3
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4answers
7k views

Calculating the minimum distance between points and polygons in QGIS

I have two vector layers: one point and one polygon and I want to calculate the minimum distance of each point from the polygons (ie the distance from the closest point of the closest polygon). Is ...
2
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1answer
51 views

Calculating Distances Between Geometry Columns of Differing SRIDs

I am attempting a relatively simple task but have been running into trouble. I have two tables, one which has lat and lon points which were geocoded using google (SRID 3857) and another table which ...
2
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1answer
86 views

Calculate longitude length in miles

Suppose I have geographic coordinates of "Saratoga, California, USA" as Latitude: 37°15.8298′ N Longitude: 122° 1.3806′ W I know from here that in case of latitude 1° ≈ 69 miles and that ...
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0answers
46 views

How to calculate the average point spacing for a layer of points in QGIS?

I have a set of points and want to calculate the average point spacing for further analysis. ArcMap has the 3D Analyst Point File Information for this but I'm searching for an alternative in QGIS. ...
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1answer
73 views

QGIS Azimuth and Distance plugin length issue

Relative newbie to QGIS and trying to figure out exactly what I'm doing wrong. A couple days ago I had azimuth and distance working perfectly. I was using it in a different project with different ...
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3answers
500 views

Toblers's Hiking Equation and Slope Dilemma

I'm trying to use Toblers's Hiking equation to determine economical backgrounds of some hillforts. The equation is anisotropic which means that the speed of movement that it calculates differs whether ...
2
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1answer
96 views

Distance to nearest hub output not correct

In QGIS 2.6, I'm working with two point layers: center of the population per census tract and stores that accept food stamps. I'm using "distance to nearest hub" to calculate nearest food stamp outlet ...