void sphcyl_c ( SpiceDouble radius,
SpiceDouble * r,
SpiceDouble * lon,
SpiceDouble * z )
This routine converts from spherical coordinates to cylindrical
VARIABLE I/O DESCRIPTION
-------- --- -------------------------------------------------
radius I Distance of point from origin.
colat I Polar angle (co-latitude in radians) of point.
slon I Azimuthal angle (longitude) of point (radians).
r O Distance of point from Z axis.
lon O angle (radians) of point from XZ plane.
z O Height of point above XY plane.
radius Distance of the point from origin.
colat Polar angle (co-latitude in radians) of the point.
slon Azimuthal angle (longitude) of the point (radians).
r Distance of the point of interest from Z axis.
lon cylindrical angle (radians) of the point from the
XZ plane. `lon' is set equal to `slon'.
z Height of the point above XY plane.
This returns the cylindrical coordinates of a point whose
position is input through spherical coordinates.
Other than the obvious conversion between coordinate systems
this routine could be used to obtain the axial projection
from a sphere to a cylinder about the z-axis that contains
the equator of the sphere. The following code fragment
illustrates this idea.
sphcyl_c ( radius, colat, lon, r, lon, z )
r = radius
r, lon, and z now contain the coordinates of the projected
point. Such a projection is valuable because it preserves the
areas between regions on the sphere and their projections to the
W.L. Taber (JPL)
E.D. Wright (JPL)
-CSPICE Version 1.0.1, 26-JUL-2016 (BVS)
Minor headers edits.
-CSPICE Version 1.0.0, 08-FEB-1998 (EDW)
spherical to cylindrical coordinates