section b of routines in rays.i

Home Manual Packages Global Index Keywords Quick Reference | # functions in rays.i - b
best_rays |
                 best_rays(rays)

         returns 5-element (x,y,z,theta,phi) representation of RAYS.
         The first dimension of RAYS may be length 3, 5, or 6 to represent
         the ray(s) in TDG/DIRT coordinates (x,y,theta), "best" coordinates
         (x,y,z,theta,phi), or internal coordinates (cos,sin,y,z,x,r),
         respectively.  The first dimension of the result always has length 5.
         The "best" coordinate system is the easiest to visualize:
         (x,y,z) represents any point on the ray, while (theta,phi)
         represents the ray direction in standard spherical coordinates
         relative to the +z-axis.  Namely, theta is the angle from the
         +z-direction to the ray direction (between 0 and pi), and phi is
         the counterclockwise angle from the +x-axis to the projection of
         the ray direction into the xy-plane, assuming xyz is a right-handed
         coordinate system.
         As a specification of a ray, this system is doubly redundant because
         the point (x,y,z) could be any point on the ray, and the underlying
         mesh through which the ray propagates is cylindrically symmetric about
         the z-axis.
         However, the slimits parameter -- used to specify the points along
         a ray where the transport integration starts and stops -- is
         measured from the point (x,y,z) specified as a part of the
         (x,y,z,theta,phi) ray coordinate.  Thus, any change in the point
         (x,y,z) on a ray must be accompanied by a corresponding change in
         the slimits for that ray.

    interpreted function, defined at i/rays.i   line 40
SEE ALSO: | form_rays, dirt_rays, internal_rays, get_s0, picture_rays