# Tagged Questions

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

0answers
128 views

### Finding density centroids within polygons in PostGIS

I want to find the highest density of OpenStreetMap nodes within a dataset of census geometries. I want to tie the census data to the location of the node which is most central in terms of population. ...
0answers
79 views

### QGIS Cross Section Profile Distance using Ellipsoid?

I am working with QGIS 1.8 and 2.6 and can't get any of the Cross Section Profile tools to provide the ellipsoid ("proper") distances. All the distances use geographic coordinates which are too long/...
0answers
346 views

### Constructing a Voronoi diagram using a complicated travel time metric

I have in my possession four sets of shapefiles: 1. Locations (points), around 1000 2. Roads (lines), each road has a speed attribute 3. Terrain (polygons), each zone also has a speed attribute 4. ...
0answers
39 views

### Calculating distances (differences?) between two regions?

I am building a machine learning system which predicts the location of tweets as a bounding box (using the google maps API among other things). Since the twitter API also supplies a bounding box, I am ...
0answers
66 views

### Find Distance Between Two Polygons

Given two polygons (point, line, or up to 8 vertices) I need to be able to calculate the shortest distance between them via code I write or a call to an API (I haven't been able to find one that does ...
0answers
76 views

### How to calculate best path between 2 points from a DEM in Qgis?

I'm analyzing the roads and paths of a region by calculating how effective the communication is in the region. First I calculated the shortest paths between the points using the actual road map. Now ...
0answers
29 views

### Creating a distance overlay that is computed by the distance of points/lines and recalculated on zooming

I created a fictional map and visualized it with d3. Now I would like to show a scale/rule so that the user can see which distance (kilometers,meters) he is currently using. I was thinking about ...
0answers
217 views

### Get Distance between two point on linestring using mysql Spatial

I have a linestring and two point on this linestrin according to my picture i want distance between two point as base of linestring please hellp me
0answers
283 views

### converting a distance to a map distance

I have a point and a polyline. I need to find the perpendicular distance between each segment of the polyline and the point. By each segemnt of the polyline I mean that, each polyline may contain more ...
0answers
449 views

### calculate total Miles in a polygon using Google Map

I have an application that allows the users to create any custom polygon layer on top of google maps, i am interested to know if their is a way to select the road layer in this polygon and then ...
0answers
926 views

### Performing a Multicriteria Analysis Using Distance Along a Road Network

There is the possibility that I will be working on a project which will look at thousands of properties in a region and measure their accessibility to different services (schools, parks, hospitals, ...
0answers
38 views

### Calculate Geometry function returns underestimated distances

I'm making a map of the Colorado Trail and obtained a set of waypoints taken down the entire trail. I projected the set of waypoints from WGS84 (unprojected) to NAD 83 UTM13N after adding to the data ...
0answers
77 views

### Measure distance between points along a line in QGIS

I have a road network and different points connected to the roads. I would like to measure the distance between several points along the roads. Basically I want to do the same like the road graph ...
0answers
29 views

### OpenLayers measurment path in 31700 projection

I have this code who works great for distance measurment on 900913 projection with 4326 display projection (bing maps + layer WMS): measureDistanceControl = new OpenLayers.Control.Measure( ...
0answers
27 views

### Using “snap pour point” to find a watershed of specific area starting from a point

I am trying to find everything downhill of a certain point in order to create a watershed of a specific area. For example, say I have a point at (x,y), and I'm interested in creating a watershed ...
0answers
69 views

### Why this pyqgis code cause crash dump in QGIS?

In ArcGIS there is gp.EucDirection to calculate Euclidean allocation, distance, and direction around a point, Is there equivalent function in pyqgis or gdal? I wrote a script with help of gene and ...
0answers
79 views

### How to calculate shortest path from points in one layer to points in another layer via roads, in QGIS

I'm a new user of QGIS (and have experience using ArcGIS but zero programming skills) and I'm looking for a way to calculate the shortest path from addresses to subway stations via a network of roads. ...
0answers
41 views

### How can I measure the distance between many polygon features and either another polygon or a line in QGIS?

I often have to manually measure the distance between a single site and other sites around it, but obviously this can get long-winded and I feel like there must be a much more efficient way of doing ...
0answers
177 views

### How to automate calculation of distance between a zip code (centroid) and an address within one line of data?

I have a large data set of federal contracts which includes two pieces of spatial data per entry (or line): the zip code in which the project took place and the address of the contractor. I am ...
0answers
365 views

### Google maps distance based on the zoom level

I have used google maps for displaying some locations using markers, based on the user's current location. User's current location is the center point of the map. The default zoom level is 12. In ...
0answers
70 views

### QGIS: distance matrix different outputs

In one of my plugins I would like to use the distance geoprocessing algorithm. When running this algorithm from the menu Vector->Analysis Tools->Distance Matrix I get a different output than running ...
0answers
102 views

### QGIS distance from point to line along a specific bearing

I've got a vector layer with points (representing customer locations) and another vector layer with a line (representing the coast line). I want to calculate a "smart" distance to coast. Specifically, ...
0answers
906 views

### GeoTools - Find distance in meters between point and path in lat/lon

I need to find distance in meters between some point with given latitude and longitude and line (on Earth) defined by several points with lat/lon coordinates. I read this questions: first second ...
0answers
424 views

### Calculate Euclidean distance to raster WITHIN multiple polygons

I am using ArcGIS 10.1 on a Windows x64 system. I am working in a study area where I have 360 000 locations of about 50 territorial animals. I have a shapefile containing 125 sometimes overlapping ...
0answers
77 views

### Needing to find parent zip code of a bunch of missing zip codes in the US

We're using MapPoint to export zip code / territory combinations. Unfortunately, the export doesn't include PO Box zip codes which mean that we're missing a lot of zip codes The PO Box zip codes are ...
0answers
112 views

### QGIS Problem in calculating the distance of points from line

I need to calculate the distance of villages ( villages as points) from a border. I have a shapefile containing the locations of villages and another one containing the border. On QGIS, I ran the '...
0answers
41 views

### How to calculate distance from point to polygon with a time frame?

Using the Near tool, I knew that I can just calculate the distance of each house to the nearest fire. However, I only want to keep fires that happened in the past 7 years for each house. For example, ...
0answers
379 views

### Create circles around a point on a map measuring the radius in hours

Disclaimer: I am not experienced in GIS and hope this question fits in this category. I was wondering whether it is somehow possible to create a circle* around a city, using Google Maps or the like, ...
0answers
519 views

### FME - calculating distance to points along a line

I am new to FME, and trying to get my head around what should be pretty straightforward issues, but I find myself going around in circles Basically I want to determine the distance (chainage) to a ...
0answers
194 views

### GeoDjango order_by('distance') not working as expected?

Using GeoDjango, I am trying to sort a list of users based on the distance from a point. It does generate a list, but its not ordered by distance, though I specify that in my query. This is the query ...
0answers
164 views

### coordinate system for calculating distance at the nation scale

I want to use ArcGIS 10.1 to calculate the straight (euclidean) distances from zip codes to their nearest city centers in about 300 U.S. metropolitan areas. I have two point shpfiles: one includes the ...
0answers
93 views

### Get distance after path distance allocation

I use ArcGIS 10.1 in Windows XP. I have a two point feature data sets One containing a single point P1 and another containing multiple points Pm. I computed the minimum-distance path from P1 to each ...
0answers
2k views

### Calculate cumulative distance between points in a dataset in ArcGIS 9.3 ArcInfo

I am working with several point datasets that I have received, with the points representing xy locations with elevation data for several levees in south Louisiana. I would like to be able to calculate ...
0answers
19 views

### Calculate distance between polygons on two separate layers using ArcGIS for Desktop?

For my purposes, I need to find for each polygon in one feature dataset (red polygons) the outemost (from edge to edge) polygon in the second feature datasets (green polygons). Paradoxically, seeking ...
0answers
45 views

### Is there any difference between gdal_proximity.py and ArcGIS Euclidean Distance?

The gdal_proximity.py description says: The gdal_proximity.py script generates a raster proximity map indicating the distance from the center of each pixel to the center of the nearest pixel ...
0answers
56 views

### Getting distance from nearest stream and elevation to nearest stream?

I need to know if there are simple commands for this 2 points: the distance from the nearest stream, D [m], defined as the length of the path that hydrologically connects the location under exam to ...
0answers
27 views

### Measure the distance between points automatically

How can I measure the distance between points referring to the same element in an automated way? In fact I've imported in QGIS buildings downloaded from two different sources and obviously they are ...
0answers
22 views

### Calculating the distance between points and parts of a underlying raster set

I need your help with a calculation of the distance between points (cities in this case) and forest (raster data). Is there a possibility to collate to every city the distance to the nearest forest ...
0answers
36 views

### Discrepancy between CAD and GIS route lengths

I have imported a route from AutoCAD which is marked every kilometre and converted it into a shapefile. I put markers every 100 m using X-Tools. There is a difference between the two sets of markers, ...
0answers
51 views

### Calculate shortest paths for each output area in catchment through road network to a single point (i.e. store)

The title sums it up pretty much. I'm looking to derive trip distributions to a single store using population data and distance within a prescribed distance catchment. I have calculated the catchment ...
0answers
48 views

### How analyze reliability of position of new point based on point data

I am working on filter for biogeographical data. It is based on citizen science principle. People put new point data to database and I want add information about "reliability" or probability (maybe ...
0answers
85 views

### Calculate distance from a point to the border of polygon (US state)

I have a point, and I want to know if it is nearer than 100 miles from some US State border (California for example). I assume that I would need to use this: US Regions State Boundaries. But if I ...
0answers
29 views

### Incorrect results returning from st_distance_spheroid query

Given a routable network table constructed by completing the guide at http://anitagraser.com/2011/02/07/a-beginners-guide-to-pgrouting/, how can I get an accurate list of all roads that are within a ...
0answers
28 views

### Build network based on shortest distance between points

Is there a way to build a network based on the shortest distances between each point of a point layer. I have occurrence data from species (as points) and want to estimate whether there are one or ...
0answers
113 views

### Google Maps Distance Matrix API - Queries per second?

I'm pretty familiar with Google's Distance Matrix API, but I'm unsure about one aspect of the Usage Limitations. The documentation states that you have access to 100 elements per query (element = ...
0answers
99 views

### How to calculate multiple distances between set of points and vector grid in PostGIS?

My set contains the following input data: A set of points and a hexagonal (vector) grid. For each cell in the grid, I want to calculate the driving-distance to each point. I thought this would be a ...
0answers
28 views

### Measuring large distances when all layers are in decimal degrees using QGIS?

I just developed a distance matrix between various points across Canada in QGIS. The distances produced are in decimal degrees, and I would like to view them in metric. I am unsure how to do this.
0answers
33 views

### Extracting distances along a line from postcode a centroid to the nearest point (bus stop)

I'm looking to measure the distance from postcode centroids (point file) in a city to the nearest bus stop (point file) along the road network (line file). In Qgis I can calculate the distance but ...
0answers
43 views

### Find points within X distance with a specific variable

I am trying to use QGIS to find points within 5 meters of each other that all have a value of <50% for a given parameter that has been loaded through a CSV file. I looked in to doing it with a ...
0answers
58 views

### Distance Analysis from single point to multiple points on vector layers

Is it possible to do the following in QGIS: Create a text file that plots the distance from a single point (stored in one layer) and multiple points (stored in another layer). I have tried to use ...