cspice_drdlat

 Abstract I/O Examples Particulars Required Reading Version Index_Entries

#### Abstract

```
CSPICE_DRDLAT computes the Jacobian of the transformation from latitudinal
to rectangular coordinates.

For important details concerning this module's function, please refer to
the CSPICE routine drdlat_c.

```

#### I/O

```
Given:

radius   scalar double precision describing the distance of a
point from the origin.

lon      scalar double precision describing the angle of the
point measured from the XZ plane in radians. The angle
increases in the counterclockwise sense about the +Z axis.

lat      scalar double precision describing the angle of the
point measured from the XY plane in radians. The angle
increases in the direction of the +Z axis.

the call:

cspice_drdlat, r, lon, lat, jacobi

returns:

jacobi   double precision 3x3 matrix describing the matrix of partial
derivatives of the conversion between latitudinal and
rectangular coordinates, evaluated at the input coordinates.
This matrix has the form

-                                -
|  dx/dr     dx/dlon     dx/dlat   |
|                                  |
|  dy/dr     dy/dlon     dy/dlat   |
|                                  |
|  dz/dr     dz/dlon     dz/dlat   |
-                                -

evaluated at the input values of 'r', 'lon' and 'lat'.
Here x, y, and z are given by the familiar formulae

x = r * cos(lon) * cos(lat)
y = r * sin(lon) * cos(lat)
z = r *            sin(lat).

```

```
None.

```

#### Particulars

```
It is often convenient to describe the motion of an object
in latitudinal coordinates. It is also convenient to manipulate
vectors associated with the object in rectangular coordinates.

The transformation of a latitudinal state into an equivalent
rectangular state makes use of the Jacobian of the
transformation between the two systems.

Given a state in latitudinal coordinates,

( r, lon, lat, dr, dlon, dlat )

the velocity in rectangular coordinates is given by the matrix
equation
t          |                               t
(dx, dy, dz)   = jacobi|             * (dr, dlon, dlat)
|(r,lon,lat)

This routine computes the matrix

|
jacobi|
|(r,lon,lat)

```

```
ICY.REQ

```

#### Version

```
-Icy Version 1.0.0, 11-NOV-2013, EDW (JPL)

```

#### Index_Entries

```
Jacobian of rectangular w.r.t. latitudinal coordinates

```
`Wed Apr  5 17:58:00 2017`