trackAngle(x)
## S3 method for class 'trip':
trackAngle(x)
## S3 method for class 'default':
trackAngle(x)
x
is a trip object, the return result has an extra element for the
start and end point of each individual trip, with value NA.
This is an optimized hybrid of "raster::bearing" and
gzAzimuth
.