latcyl_c

 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

```   void latcyl_c ( SpiceDouble    radius,
SpiceDouble    lon,
SpiceDouble    lat,
SpiceDouble *  r,
SpiceDouble *  lonc,
SpiceDouble *  z )

```

#### Abstract

```   Convert from latitudinal coordinates to cylindrical coordinates.
```

```   None.
```

#### Keywords

```   CONVERSION,  COORDINATES

```

#### Brief_I/O

```   VARIABLE  I/O  DESCRIPTION
--------  ---  --------------------------------------------------
radius     I   Distance of a point from the origin.
lon        I   Angle of the point from the XZ plane in radians.
lat        I   Angle of the point from the XY plane in radians.
r          O   Distance of the point from the z axis.
lonc       O   Angle of the point from the XZ plane in radians.
z          O   Height of the point above the XY plane.
```

#### Detailed_Input

```   radius     Distance of a point from the origin.

lon        Angle of the point from the XZ plane in radians.

lat        Angle of the point from the XY plane in radians.
```

#### Detailed_Output

```   r          Distance of the point from the z axis.

lonc       Angle of the point from the XZ plane in radians.
`lonc' is set equal to `lon'.

z          Height of the point above the XY plane.
```

#### Parameters

```   None.
```

#### Exceptions

```   Error free.
```

#### Files

```   None.
```

#### Particulars

```   This routine returns the cylindrical coordinates of a point
whose position is input in latitudinal coordinates.

Latitudinal coordinates are defined by a distance from a central
reference point, an angle from a reference meridian, and an angle
above the equator of a sphere centered at the central reference
point.
```

#### Examples

```   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.

latcyl_c ( radius,  lon, lat, &r,  &lon, &z );

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
cylinder.
```

#### Restrictions

```   None.
```

#### Literature_References

```   None.
```

#### Author_and_Institution

```   E.D. Wright     (JPL)
W.L. Taber      (JPL)
```

#### Version

```   -CSPICE Version 1.0.1, 26-JUL-2016 (BVS)

```   latitudinal to cylindrical coordinates
`Wed Apr  5 17:54:38 2017`