Difference between two angles

returns
the angular difference between adjacent elements of `delta`

= angdiff(`alpha`

)`alpha`

along
the first dimension whose size does not equal 1. If `alpha`

is
a vector of length *n*, the first entry is subtracted
from the second, the second from the third, etc. The output, `delta`

,
is a vector of length *n-1*. If `alpha`

is
an *m*-by-*n* matrix with *m* greater
than 1, the output, `delta`

, will be a matrix of
size *m-1*-by-*n*.