Hello, Did you take a look et st_offsetcurve ? The documentation says: " For positive distance the offset will be at the left side of the input line and retain the same direction."
Hug James David Smith <[email protected]> a écrit : Hi there, Just looking for some general thoughts and guidance on the best way to do this please. What I have is about 50,000 linestrings of varying length. They are in a projected coordinate system (OSGB36). They represent people walking around a city. The routing however has been done as road centrelines. So what I would like to do, is to move each line 3 metres to the left so that it gives a better representation of where they actually walked. I realise this is very inexact, but it will do for my purposes. So does anyone have any thoughts about how to do this? Obviously 'left' is a relative term as it will depend on the direction of travel. I think maybe I need to break apart the linestring into collections of two points. XY_start and XY_end. Then calculate the angle between them. The add or subtract 3 metres onto one of the sets of coordinates in one direction, depending on what the result of the angle calculation was. Once I've done this, I could then recombine all the sets of points back into linestrings. Does this sound like a reasonable approach? (Whether I'll actually be able to do it or not is another thing). Thanks James _______________________________________________ postgis-users mailing list [email protected] http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users _______________________________________________ postgis-users mailing list [email protected] http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
