[postgis-users] Calculate accumulative bearing given a zig-zagging line

[Shaozhong SHI]

On Thursday, 17 February 2022, Sandro Santilli <strk at kbt.io> wrote:

> On Thu, Feb 17, 2022 at 08:21:24AM +0000, Shaozhong SHI wrote:
> > Is there a function for calculating accumulative bearing given a
> > zig-zagging line?
> >
> > If we set a segment to travel towards north and its bearing is 0. Next
> > segment may zig-zag towards 10 degrees.  The following one may zig-zag
> > towards -5 degree.
> >
> > Calculating accumulative bearing may assist us to check whether a line
> does
> > a U-turn.  If accumulative bearing is greater than 180, it is a U-turn.
> >
> > Is there such function available?
>
> You can use ST_Azimuth, some normalization routine to turn the radians
> into a signed value and the sum aggregate to "accumulate" it.
>
> --strk;
> This is interesting.  Can you expand and do a demo?

Regards,
David
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