Index of Functions: A B C D E F G H I J K L M N O P Q R S T U V W X
Index Page cylsph_c
Table of contents
Procedure Abstract Required_Reading Keywords Brief_I/O Detailed_Input | Detailed_Output Parameters Exceptions Files Particulars Examples | Restrictions Literature_References Author_and_Institution Version Index_Entries
#### Procedure
       cylsph_c ( Cylindrical to spherical )

       void cylsph_c ( SpiceDouble    r,
                       SpiceDouble    clon,
                       SpiceDouble    z,
                       SpiceDouble *  radius,
                       SpiceDouble *  colat,
                       SpiceDouble *  slon )
#### Abstract
       Convert from cylindrical to spherical coordinates.
#### Required_Reading
       None.
#### Keywords
       CONVERSION
       COORDINATES
#### Brief_I/O
       VARIABLE  I/O  DESCRIPTION
       --------  ---  -------------------------------------------------
       r          I   Distance of point from z axis.
       clon       I   Angle (radians) of point from XZ plane.
       z          I   Height of point above XY plane.
       radius     O   Distance of point from origin.
       colat      O   Polar angle (co-latitude in radians) of point.
       slon       O   Azimuthal angle (longitude) of point (radians).
#### Detailed_Input
       r           is the distance of the point of interest from z axis.

       clon        is the cylindrical angle (radians) of the point from the
                   XZ plane.

       z           is the height of the point above XY plane.
#### Detailed_Output
       radius      is the distance of the point from origin.

       colat       is the polar angle (co-latitude in radians) of the point.
                   The range of `colat' is [-pi, pi].

       slon        is the azimuthal angle (longitude) of the point
                   (radians). `slon' is set equal to `clon'.
#### Parameters
       None.
#### Exceptions
       Error free.
#### Files
       None.
#### Particulars
       This returns the spherical coordinates of a point whose position
       is input through cylindrical coordinates.
#### Examples
       The numerical results shown for these examples may differ across
       platforms. The results depend on the SPICE kernels used as
       input, the compiler and supporting libraries, and the machine
       specific arithmetic implementation.

       1) Compute the cylindrical coordinates of the position of the
          Moon as seen from the Earth, and convert them to spherical
          and rectangular coordinates.

          Use the meta-kernel shown below to load the required SPICE
          kernels.

             KPL/MK

             File name: cylsph_ex1.tm

             This meta-kernel is intended to support operation of SPICE
             example programs. The kernels shown here should not be
             assumed to contain adequate or correct versions of data
             required by SPICE-based user applications.

             In order for an application to use this meta-kernel, the
             kernels referenced here must be present in the user's
             current working directory.

             The names and contents of the kernels referenced
             by this meta-kernel are as follows:

                File name                     Contents
                ---------                     --------
                de421.bsp                     Planetary ephemeris
                naif0012.tls                  Leapseconds

             \begindata

                KERNELS_TO_LOAD = ( 'de421.bsp',
                                    'naif0012.tls'  )

             \begintext

             End of meta-kernel

          Example code begins here.

          /.
             Program cylsph_ex1
          ./
          #include <stdio.h>
          #include "SpiceUsr.h"

          int main( )
          {

             /.
             Local variables
             ./
             SpiceDouble          clon;
             SpiceDouble          colat;
             SpiceDouble          et;
             SpiceDouble          lt;
             SpiceDouble          pos    [3];
             SpiceDouble          r;
             SpiceDouble          radius;
             SpiceDouble          rectan [3];
             SpiceDouble          slon;
             SpiceDouble          z;

             /.
             Load SPK and LSK kernels, use a meta kernel for
             convenience.
             ./
             furnsh_c ( "cylsph_ex1.tm" );

             /.
             Look up the geometric state of the Moon as seen from
             the Earth at 2017 Mar 20, relative to the J2000
             reference frame.
             ./
             str2et_c ( "2017 Mar 20", &et );

             spkpos_c ( "Moon", et, "J2000", "NONE", "Earth", pos, &lt );

             /.
             Convert the position vector `pos' to cylindrical
             coordinates.
             ./
             reccyl_c ( pos, &r, &clon, &z );

             /.
             Convert the cylindrical coordinates to spherical.
             ./
             cylsph_c ( r, clon, z, &radius, &colat, &slon );

             /.
             Convert the spherical coordinates to rectangular.
             ./
             sphrec_c ( radius, colat, slon, rectan );

             printf( " \n" );
             printf( "Original rectangular coordinates:\n" );
             printf( " \n" );
             printf( " X           (km):  %19.8f\n", pos[0] );
             printf( " Y           (km):  %19.8f\n", pos[1] );
             printf( " Z           (km):  %19.8f\n", pos[2] );
             printf( " \n" );
             printf( "Cylindrical coordinates:\n" );
             printf( " \n" );
             printf( " Radius      (km):  %19.8f\n", r );
             printf( " Longitude  (deg):  %19.8f\n", clon*dpr_c ( ) );
             printf( " Z           (km):  %19.8f\n", z );
             printf( " \n" );
             printf( "Spherical coordinates:\n" );
             printf( " \n" );
             printf( " Radius      (km):  %19.8f\n", radius );
             printf( " Colatitude (deg):  %19.8f\n", colat*dpr_c ( ) );
             printf( " Longitude  (deg):  %19.8f\n", slon*dpr_c ( ) );
             printf( " \n" );
             printf( "Rectangular coordinates from sphrec_c:\n" );
             printf( " \n" );
             printf( " X           (km):  %19.8f\n", rectan[0] );
             printf( " Y           (km):  %19.8f\n", rectan[1] );
             printf( " Z           (km):  %19.8f\n", rectan[2] );
             printf( " \n" );

             return ( 0 );
          }

          When this program was executed on a Mac/Intel/cc/64-bit
          platform, the output was:

          Original rectangular coordinates:

           X           (km):      -55658.44323296
           Y           (km):     -379226.32931475
           Z           (km):     -126505.93063865

          Cylindrical coordinates:

           Radius      (km):      383289.01777726
           Longitude  (deg):         261.65040211
           Z           (km):     -126505.93063865

          Spherical coordinates:

           Radius      (km):      403626.33912495
           Colatitude (deg):         108.26566077
           Longitude  (deg):         261.65040211

          Rectangular coordinates from sphrec_c:

           X           (km):      -55658.44323296
           Y           (km):     -379226.32931475
           Z           (km):     -126505.93063865

       2) Create a table showing a variety of cylindrical coordinates
          and the corresponding spherical coordinates.

          Corresponding spherical and cylindrical coordinates are
          listed to three decimal places. All input and output angles
          are in degrees.

          Example code begins here.

          /.
             Program cylsph_ex2
          ./
          #include <stdio.h>
          #include "SpiceUsr.h"

          int main( )
          {

             /.
             Local parameters.
             ./
             #define NREC         11

             /.
             Local variables.
             ./
             SpiceDouble          colat;
             SpiceDouble          radius;
             SpiceDouble          rclon;
             SpiceDouble          slon;

             SpiceInt             i;

             /.
             Define the input cylindrical coordinates. Angles
             in degrees.
             ./

             SpiceDouble          r      [NREC] = { 0.0, 1.0, 1.0,
                                                    0.0, 1.0, 1.0,
                                                    0.0, 1.0, 1.0,
                                                    0.0, 0.0      };

             SpiceDouble          clon   [NREC] = {   0.0,   0.0,  90.0,
                                                      0.0, 180.0, -90.0,
                                                      0.0,  45.0, 180.0,
                                                    180.0,  33.0        };

             SpiceDouble          z      [NREC] = {  0.0,  0.0,  0.0,
                                                     1.0,  1.0,  0.0,
                                                    -1.0,  0.0, -1.0,
                                                     1.0,  0.0       };

             /.
             Print the banner.
             ./
             printf( "    r       clon      z      radius   colat     slon \n" );
             printf( " -------  -------  -------  -------  -------  -------\n" );

             /.
             Do the conversion. Output angles in degrees.
             ./
             for ( i = 0; i < NREC; i++ )
             {

                rclon = clon[i] * rpd_c ( );

                cylsph_c ( r[i], rclon, z[i], &radius, &colat, &slon );

                printf( "%8.3f %8.3f %8.3f ", r[i], clon[i], z[i] );
                printf( "%8.3f %8.3f %8.3f\n",
                        radius, colat * dpr_c ( ), slon  * dpr_c ( ) );

             }

             return ( 0 );
          }

          When this program was executed on a Mac/Intel/cc/64-bit
          platform, the output was:

              r       clon      z      radius   colat     slon
           -------  -------  -------  -------  -------  -------
             0.000    0.000    0.000    0.000    0.000    0.000
             1.000    0.000    0.000    1.000   90.000    0.000
             1.000   90.000    0.000    1.000   90.000   90.000
             0.000    0.000    1.000    1.000    0.000    0.000
             1.000  180.000    1.000    1.414   45.000  180.000
             1.000  -90.000    0.000    1.000   90.000  -90.000
             0.000    0.000   -1.000    1.000  180.000    0.000
             1.000   45.000    0.000    1.000   90.000   45.000
             1.000  180.000   -1.000    1.414  135.000  180.000
             0.000  180.000    1.000    1.000    0.000  180.000
             0.000   33.000    0.000    0.000    0.000   33.000
#### Restrictions
       None.
#### Literature_References
       None.
#### Author_and_Institution
       J. Diaz del Rio     (ODC Space)
       B.V. Semenov        (JPL)
       W.L. Taber          (JPL)
       E.D. Wright         (JPL)
#### Version
       -CSPICE Version 1.1.0, 02-JUL-2021 (JDR)

           Changed the argument names "lonc" and "lon" to "clon" and
           "slon" for consistency with other routines.

           Edited the header to comply with NAIF standard.
           Added complete code examples.

       -CSPICE Version 1.0.2, 26-JUL-2016 (BVS)

           Minor headers edits.

       -CSPICE Version 1.0.1, 08-FEB-1998 (EDW)

           Corrected and clarified header entries.

       -CSPICE Version 1.0.0, 25-OCT-1997 (EDW) (WLT)
#### Index_Entries
       cylindrical to spherical
#### Link to routine cylsph_c source file cylsph_c.c

    Fri Dec 31 18:41:03 2021