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# Questions tagged [direction]

The distance-independent relationship between two points in space that specifies the angular position of either with respect to the other

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### How can I calculate the bearing between two points in PostGIS?

How can I find the bearing between two points in PostGIS? Please specify in your answer whether or not the method producing a bearing on the spheroid, or a planar bearing.
623 views

### Which weather on my road? Looking for a spatial weather forecast web service

My friend Bob goes from A to B leaving tomorrow morning at 6:00. There are many direction services that indicates him short, fast and/or cheap routes. Bob does not like to drive under the rain and ...
4k views

### What determines “west” in Antarctica?

Hopefully this isn't so far afield as to get banned - apologies in advance to those who think it doesn't belong. This article discusses a region of Antarctica which is described as "West Antarctica". ...
18k views

### Showing polyline direction in ArcGIS for Desktop (ArcMap)?

How can I show the direction of a polyline as it was digitised? I need this to check if my network analysis is obeying one way streets. I know of a tool in Xtools that can do this but my trial ...
925 views

### Slope, in which direction?

I have a dilemma? I work with a slope terrain. Slope field is done by a percentage of 10%. My question is, in which direction is oriented this pixel, or any pixels? It is important to know to what ...
7k views

### Displaying arrows on pipes from upstream to downstream using QGIS?

I am trying to display arrows on pipes of a sewer network so their direction is from upstream to downstream edges of the pipes. I have managed to display those arrows on a polyline layer (which is ...
300 views

### Walking route that covers the largest area in shortest distance

I regularly need to walk across field searching for bird nests. The field are often squares or polygons and the bird nests could be anywhere on the ground in the field. To stand the best chance of ...
417 views

### Creating Direction data in QGIS between two layers?

Can I do it in Qgis, that there are two layers, a target layer and an input layer, and I ascertain with an algorithm so that the closest points on the input layer are on the target layer in what ...
287 views

### Create a projection to emphasize a given direction in ArcMap?

Suppose one had a dataset (centered on a given coordinate) of lines that were very close together in terms of longitude but also had important turns/bends far separated by latitude. In order to map ...
717 views

### Labeling (one-way) streets in QGIS?

I followed instructions in this answer to Creating Directional Flow Arrows for sewer lines? to add directional arrows to the one-way streets on a map I'm creating. I've currently created a marker ...
2k views

### Showing directional line symbol in ArcGIS for Desktop?

Is this possible in ArcGIS to have variable number of arrows on the line to show direction? This is an ArcGIS example, where I can have fixed (1,2,3,4,5...) number of arrows and it stays the same ...
826 views

### Determining the direction of polygons?

Is there a way in QGIS to figure out the direction of a polygon, if there are no values given? What I need to know is if a polygon is directed to the south. I want to know the direction of a house ...
2k views

### How do I find least cost path over a DEM based on slope magnitude and direction?

What sort of algorithms can I use to find a least cost path through a DEM where it costs more to traverse a cell going downhill or uphill than it does to follow the contour of the land? All the ...
357 views

I try to create an application for taxis. The application will be GMap based. On the map will be marked the region in which the taxi driver is working in. The region will be a polygon designed by ...
815 views

### Determining direction of polygons using QGIS?

Is it possible to get the direction of the longest side of a rectangle in QGIS? I know how to get the direction of a line layer. But I need to know the direction of a polygon. One could start at ...
126 views

### Relative position of nodes

I am studying bird movements and have tracked their locations, ie from flower 1 to flower 2 to flower 3 etc. Each point is mapped out. I am trying to work out the relative direction for each movement ...
3k views

### Changing (flipping) line direction in QGIS?

I have river network in QGIS. I draw opposite direction one of the rivers. Now I want to change direction of that river. How can I do that in QGIS 3? (As I know it is flip in ArcGIS)
118 views

### Standard direction format in GIS software

I am working on an application, where the user can place some items on a map. Some of these items have a direction, currently saved as radians where 0 is towards right/east. We want to enable the user ...
6k views

### google maps V3 : in javascript api, render route obtained with web api

I have to obtain route directions with the Google maps v3 WEB (http request) api (computations are made server-side, based on this data, without client interaction, so no JS available). Then, the ...
4k views

### ArcMap - Display direction of points

I imported a few geotagged images and created a points shape showing their locations (or more accurately, the location of the camera) with the "Geotagged Photos to Points" tools. The attribute table ...
2k views

### Getting the compass point given longitude, latitude and direction in degrees

I have this data gathered using a GPS device No. Time Longitude Latitude Speed(Km/h) Compass point Direction (deg) 1 10/20/15 1:34 40.11724 -3.21032 11 Northwest ...
737 views

### Problem with flow lines in ArcMap

As a part of my PhD I have to map the rivers of Northern Peloponnese, Greece. I have downloaded two DEMs from Nasa Reverb, which I connected with "mosaic to new raster". I have started the usual ...
1k views

### Understanding percentage drop-raster (flow direction-tool)

I'm creating a Topographic Wetness Index using a python script (http://arcscripts.esri.com/details.asp?dbid=16750) As I don't want this just to be a blackbox, I'm trying to understand the different ...
603 views

### Right-hand-rule in QGIS

It seems that there isn't a plugin to perform the right-hand-rule on a layer or selected features. Can this be done by using some Python code? Is there a function that works in the same way as ...
426 views

### How to deal with direction in pgr_ksp (K shortest path)?

I am working on an Android app for navigation with PostGIS and pgrouting. I have implemented pgr_dijkstra and it's working fine. I am not considering direction in routing at this point and just want ...
159 views

### Calculate polygon main dircetion and create line from it - POSTGIS

I would like to find out the orientation of a polygon and create a line of that direction. See image below.
488 views

### How to create a symbol with directional arrows in QGIS 3?

This is the same as this question for ArcGIS: Creating Directional Flow Arrows for sewer lines? but for QGIS. I tried to follow the same approach as in ArcGIS, but I keep missing the mark. I think I ...
288 views

### Query Features in Certain Direction

I have a polyline that I would like to query features that are on it's left, right, top, bottom. I am not looking for the features surrounding it but for features that are on a certain location from ...
181 views

### Change direction of polylines from DEM data

I am trying to define the direction of my polylines (which represent gutters in a drainage system). Does anyone know if it is possible to define the direction based on elevation data extracted from a ...
132 views

### Dissolving lines with same directions using ArcGIS Desktop?

I have a feature class containing road polylines which has to be dissolved by some fields. But recently noticed that if some road has same atrtributes but different directions, Dissolve tool doesn't ...
1k views

### Identifying side of point from closest polyline in ArcMap?

I have a set of polylines (a network of streams and rivers) with information on the left and right side of the streams on riparian structure. I also have locations (points) of either side of the lines....
688 views

### Generating KML with arrow styling?

I have a Network GIS which I have made in QGIS and has direction arrow, but as soon as I export it to KML file I can just see the polylines without the direction. Is there a way to get the ...
181 views

### How to display bidirectional flows?

I'm working on a map showing oil shipping. Basically, I have a a series of nodes/line segments that make up the shipping network. I've joined the sums of oil that traveled along each node, so can ...
360 views

### How to deal with Roundabouts in PgRouting

Can anybody guide me to to deal with roundabouts in pgrouting?? I have some roundabouts in my road network and when i try to make route from one point to another, it gives me wrong direction where it ...
1k views

### Driving directions and multi-modal route planning service for a city with OpenStreetMap data

First off I'd like to mention that I've never come close to anything-GIS until a few weeks ago when I thought of this. So please expect some layman's questions. I'm looking to create driving ...
489 views

### Is there an open source directions webclient for pgRouting like the directions API from Google?

I am looking for an open source webclient with (Google) directions functionality (like draggable lines to create extra waypoints) based on an pgrouting database (with an osm2pgrouting topology). I ...
67 views

### Given a line find whether another line is along side, N,E,S,W or not

I have a shapefile representing roads (Black) and I need to know whether another line object (Red) is to the side of it. Including the orientation between them, to define whether the Red line lies to ...
333 views

### Show flow direction for pipes as arrows in QGIS [duplicate]

I have a vector layer (line features) which consists of different pipes. In the attribute data I have fields that indicate the upstream elevation and downstream elevation values. I am trying to ...
385 views

### How often do directions services update their OSM data?

Not sure if this is the right place to ask but I figured I would give it a shot. I'm working on an interactive map for a campus, I performed some edits to openstreetmaps and I can see the changes on ...
2k views

### Arrow flow lines from a contour map

using QGIS (or even GRASS) is it possible to label a contour lines shape with arrows that indicate the flow direction? Briefly: I have a point shape with elevation values. I make an interpolation map ...
1k views

### Does OSM data contain direction of travel?

I was looking for Direction of Travel (DOT) information inside OpenStreetMap shapefiles, but only I've just found "ONEWAY = 1 or 0", but nothing about its direction. If I work on an OSM editor, I can ...
6k views

### Finding compass direction between two distant GPS points?

I have a Latitude & Longitude for two locations (me in the West, him across the country), and a web-calculated GPS point for each. I'm trying to figure out which direction -- per my compass -- to ...
461 views

### Which projected coordinate system for whole China?

I want to project data of China. I'm not concerned with trying to preserve areal or directional relationships but preserving distances would be nice. Does such a coordinate system exist?
1k views

### how feasible is building my own map server? providing GeoCoding, Directions and Navigation

My need is a heavy use of routing. same as Google's Directions API. I'm looking for a viable alternative to abusing google and paying them too much. how difficult is it to have my own server for that ...
1k views

### How to get the Flow or directional raster map using GRASS?

Aside from using r.fill.dir in GRASS, is this the script to produce the Flow or directional raster map? Is the output for the script the following graphic? http://grass.fbk.eu/grass63/screenshots/...
203 views

### postgis How can I obtain directional buffer?

I have a geometry (polygon) which I want to extend with a buffer while testing on it in a where clause. The problem is that I would like the buffer to be only applied according to one or more ...
979 views

### Drawing line with lon, lat, distance and azimuth?

I have table in PostGIS with lon, lat, distance and azimuth columns. I want to make Geoserver draw a line through first point with given length and direction. I can turn lon and lat to geometry in ...
372 views

### ArcGIS lines to polygons without holes

I have a dataset with contours. Depression contours are separate of the normal contours and need to be digitized counter-clockwise. Still, there are usually some faulty ones with wrong direction and ...