# Tag Info

2

UK postcodes are based on the number of addresses and not area. Postcodes in rural areas are considerably larger by orders of magnitude than those in dense urban areas. In fact, large blocks of flats can even have more than one postcode at the level you mention, so you then have a problem of multiple postcodes occupying the same area, which in 2D space will ...

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The only accurate way to determine the area of a postcode is to purchase the Ordnance Survey's Codepoint with polygons product. This will also give you the number of delivery points within each postcode.

1

Is this being done in Arc or QGIS or something? What is the desired outcome? Not sure about the vehicle you will use to represent your data, but it sounds like you want to make sure your averages are mutually exclusive to the quadrant that the data is coming from. So, the red group (ABCD) needs to only consider those pieces of data to infer the average for ...

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Assuming that OS mean Ordinance Survey then see http://www.movable-type.co.uk/scripts/latlong-gridref.html and http://www.movable-type.co.uk/scripts/latlong-convert-coords.html . Ther is exelent example howto implement conversion. Another option if you for systems that use EPSG codes 27700 and 7405 seem to be relevant ids (not necessarily correct). Target ...

3

X and Y are in meters (if this is the UK national grid), so compute X' = round(X + 1609.344 cos(θ)) and Y' = round(X + 1609.344 sin(θ)), for θ ∈ [−π, π], and convert the results to grid references. There's small error in this approach (X and Y differ from true distances by a scale factor which differs slightly from one).

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Here's how to compute a parallel path. Initial path is Moscow to Sevastopol. First, I assume that the waypoints lie on a geodesic. So the perpendicular direction is found just by adding 90° to the azimuth of the geodsic. Next I treat the more general case where there may be changes in direction at the way points; for this I compute a mean direction ...

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If you project (transform) to plane coords, do the coordinate geometry (cogo), and project back to geographic coords, you must first choose the right map projection to use. There are very many and each introduces some distortions. Another option is to stay on the sphere, and perform spherical (or geodetic) coordinate geometry. Those are much more complex, ...

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You can use the Haversine formula in conjunction with basic trig to iterate a series of vertices describing your circle. Alternatively, if you have access to a GIS (e.g. ArcGIS, QGIS, PostGIS etc) or a GIS API (e.g. OGR, Shapely, GeoTools) you could simply buffer the point by one mile. E.g. for PostGIS you could use ST_Distance_sphere or ...

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In GRASS GIS version 7 (actually not stable) there is the command r.skyview (based on the command r.horizon, available also in the stable GRASS v.6). It reads a raster image representing a terrain model, with pixel value corresponding to terrain feature heights (e.g. building heights) and calculates, for each pixel, the "skyview factor". You need first to ...

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The question is pretty complicated. What you are asking about is calculations on the surface of the Earth, which is called spherical trigonometry. To get even more precise you need to use an ellipsoidal model of the Earth. I'd suggest you use a program that can already do this for you, but if you want to do it yourself, here's a link to start on. The ...

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