angdist
Returns the angular distance in radians between two vectors. The input vectors
do not have to be normalised. For almost colinear or anti-colinear vectors, renders
numerically more accurate results than the of the scalar product.
Location in HEALPix directory tree: src/f90/mod/pix_tools.F90
FORMAT
call angdist(
v1, v2, dist
)
ARGUMENTS
name & dimensionality |
kind |
in/out |
description |
|
|
|
|
v1(3) |
DP |
IN |
cartesian vector. |
v2(3) |
DP |
IN |
cartesian vector. |
dist |
DP |
OUT |
angular distance in radians between the 2 vectors. |
EXAMPLE:
use healpix_types
use pix_tools, only : angdist
real(DP) :: dist, one = 1.0_dp
call angdist((/1,2,3/)*one, (/1,2,4/)*one, dist)
print*, dist
Returns the angular distance between 2 vectors.
RELATED ROUTINES
This section lists the routines related to angdist
-
ang2vec
- converts the position angles of a point on the sphere
into its 3D position vector.
-
vec2ang
- converts the 3D position vector of point into its position
angles on the sphere.
-
vect_prod
- computes the vector product between two 3D vectors
Version 3.82, 2022-07-28