Module Gradient Vector from Polar to Cartesian Coordinates
Converts gradient vector from polar coordinates (direction or aspect angle and length or tangens of slope) to directional components (Cartesian).
The module supports three conventions on how the angle of direction can be supplied:
(a) mathematical: direction angle is zero in East direction and the angle increases counterclockwise
(b) geographical: direction angle is zero in North direction and the angle increases clockwise
(c) zero direction and orientation are user defined
- Author: Victor Olaya & Volker Wichmann (c) 2004-2010
 
- Specification: grid
 
- Menu: Grid|Calculus|Conversions
 
Parameters
|   | Name | Type | Identifier | Description | Constraints | 
| Input | Direction | Grid (input) | DIR | - | - | 
 | Length | Grid (input) | LEN | - | - | 
| Output | X Component | Grid (output) | DX | - | - | 
 | Y Component | Grid (output) | DY | - | - | 
| Options | Polar Angle Units | Choice | UNITS | - | Available Choices: [0] radians [1] degree Default: 0 | 
 | Polar Coordinate System | Choice | SYSTEM | - | Available Choices: [0] mathematical [1] geographical [2] user defined Default: 1 | 
 | User defined Zero Direction | Floating point | SYSTEM_ZERO | given in degree clockwise from North direction | Minimum: 0.000000 Maximum: 360.000000 Default: 0.000000 | 
 | User defined Orientation | Choice | SYSTEM_ORIENT | - | Available Choices: [0] clockwise [1] counterclockwise Default: 0 | 
Command-line
Usage: saga_cmd grid_calculus 16 [-DIR <str>] [-LEN <str>] [-DX <str>] [-DY <str>] [-UNITS <str>] [-SYSTEM <str>] [-SYSTEM_ZERO <str>] [-SYSTEM_ORIENT <str>]
  -DIR:<str>          	Direction
	Grid (input)
  -LEN:<str>          	Length
	Grid (input)
  -DX:<str>           	X Component
	Grid (output)
  -DY:<str>           	Y Component
	Grid (output)
  -UNITS:<str>        	Polar Angle Units
	Choice
	Available Choices:
	[0] radians
	[1] degree
	Default: 0
  -SYSTEM:<str>       	Polar Coordinate System
	Choice
	Available Choices:
	[0] mathematical
	[1] geographical
	[2] user defined
	Default: 1
  -SYSTEM_ZERO:<str>  	User defined Zero Direction
	Floating point
	Minimum: 0.000000
	Maximum: 360.000000
	Default: 0.000000
  -SYSTEM_ORIENT:<str>	User defined Orientation
	Choice
	Available Choices:
	[0] clockwise
	[1] counterclockwise
	Default: 0