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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15 views

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

I am working on a android app for navigation with PostGIS and pgrouting. I have implemented pgr_dijkstra and its working fine. I am not considering direction in routing at this point and just want ...
0
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1answer
54 views

lines: distance-direction computation queries

From the distance and direction tutorial below: How to add Direction and Distance to attribute table? that uses: 1 - xat (0 ), xat (-1 ) and yat (0 ), yat (-1) for start and end points of lines; ...
2
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1answer
119 views

Knowing acceleration, gyro and compass data how to calculate north direction [closed]

I have a small video camera with an attached sensor. I can get from the sensor his acceleration, gyro and compass data. Knowing this data I need to rotate the camera so that it will look strictly ...
3
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2answers
335 views

How to show polyline direction in ArcGIS for Desktop (ArcMap)?

can someone tell me how I can 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 ...
4
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1answer
167 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 ...
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0answers
26 views

What is proper bearing for plat ties to monuments?

I had a 'discussion' with an engineer about the proper way to describe a bearing on a plat (survey of land) that ties the plat to a known survey monument. He stated that it should be from the point of ...
2
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2answers
228 views

How to display 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 ...
0
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0answers
59 views

i need to create a simple gps, which api is the fastest and easiest?

I need to create something v.simple the map should get the location of the user, and i would send it a 2nd requested locations lat-lng from my db I need the map to give the directions which the ...
0
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1answer
135 views

Updating a column with line direction in MapInfo

I was wondering if there is a way to update a column in MapInfo with the digitised line direction. I have two TAB files, one is complete lines and the other is sections of the same lines (both have a ...
1
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0answers
244 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 ...
0
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0answers
90 views

Switching between different feature sets / Change orientation of Openlayers Map

Setup Entities postgis table: id | name | the_geom | campus_id 1 | bldg_1 | <b1_geom> | 1 2 | bldg_2 | <b2_geom> | 2 3 | bldg_3 | <b3_geom> | 1 4 | bldg_4 | ...
2
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0answers
351 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 ...
6
votes
1answer
342 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". ...
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0answers
67 views

How to indicate a change in transport mode for directions in a multimodal dataset

When I solve a route and generate directions for my multimodal dataset, the end product is not very user friendly: The pedestrian started walking along Main Street and then boarded a bus to travel ...
4
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0answers
108 views

Advanced GMaps directions

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 ...
1
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1answer
202 views

Small Idea to get best path between two points

Guys I don't know if its a good place to post ideas or to ask general questions. Still as the question is related with maps service, I am posting it here. If it's not the right place, please move me ...
6
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1answer
513 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 ...
1
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0answers
167 views

Avoid backtracking while creating loop in Google Map API 3

I am trying to build a solution where i would create loop by google map. My first and only business rule is there should not be any repeated route. But with my demo ...
2
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2answers
369 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 ...
1
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1answer
1k 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 ...
3
votes
1answer
312 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 ...
2
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2answers
189 views

Working out parcel direction

I am looking at applying a direction indicator to land parcels and houses (in MasterMap). effectively, I am looking at applying a direction indicator to the land and the buildings associated to the ...
10
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2answers
242 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 ...
3
votes
1answer
348 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 this the output for the script ...
14
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2answers
3k views

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.