Tool Fractal Brownian Noise
This tool uses uniform random to create a grid that resembles fractal Brownian noise (FBN). The advantage of FBN noise is that it appears to have texture to the human eye, that resembles the types of textures that are observed in nature; terrains, algae growth, clouds, etc. The degree of texture observed in the FBN grid is dependent upon the sizes of the wavelengths chosen. The wavelengths should be chosen so they increase in size (a doubling of successive wavelengths is a good point to start). The greater the magnitude of the "ramp" of successive wavelengths the greater the texture in the FBN grid. 
- Author: A.Jack, O.Conrad (c) 2017
 
- Menu: Grid|Calculus|Grid Generation
 
Parameters
|   | Name | Type | Identifier | Description | Constraints | 
| Input | Target System (*) | Grid (optional input) | TEMPLATE | use this grid's system for output grids | - | 
| Output | Fractal Brownian Noise | Grid (output) | OUT_GRID | - | - | 
| Options | Target Grid System | Choice | DEFINITION | - | Available Choices: [0] user defined [1] grid or grid system Default: 0 | 
 | Cellsize | Floating point | USER_SIZE | - | Minimum: 0.000000 Default: 1.000000 | 
 | West | Floating point | USER_XMIN | - | Default: 0.000000 | 
 | East | Floating point | USER_XMAX | - | Default: 100.000000 | 
 | South | Floating point | USER_YMIN | - | Default: 0.000000 | 
 | North | Floating point | USER_YMAX | - | Default: 100.000000 | 
 | Columns | Integer | USER_COLS | Number of cells in East-West direction. | Minimum: 1 Default: 100 | 
 | Rows | Integer | USER_ROWS | Number of cells in North-South direction. | Minimum: 1 Default: 100 | 
 | Fit | Choice | USER_FITS | - | Available Choices: [0] nodes [1] cells Default: 0 | 
 | Grid System | Grid system | SYSTEM | - | - | 
 | Scaling | Choice | SCALING | - | Available Choices: [0] linear [1] geometric Default: 1 | 
 | Maximum Scale | Floating point | MAX_SCALE | - | Minimum: 0.000000 Default: 1.000000 | 
 | Steps | Integer | STEPS | - | Minimum: 1 Default: 8 | 
 | Noise Range | Value range | RANGE | - | - | 
| (*) optional | 
Command-line
Usage: saga_cmd grid_calculus 17 [-DEFINITION <str>] [-USER_SIZE <double>] [-USER_XMIN <double>] [-USER_XMAX <double>] [-USER_YMIN <double>] [-USER_YMAX <double>] [-USER_COLS <num>] [-USER_ROWS <num>] [-USER_FITS <str>] [-TEMPLATE <str>] [-OUT_GRID <str>] [-SCALING <str>] [-MAX_SCALE <double>] [-STEPS <num>] [-RANGE_MIN <double>] [-RANGE_MAX <double>]
  -DEFINITION:<str>  	Target Grid System
	Choice
	Available Choices:
	[0] user defined
	[1] grid or grid system
	Default: 0
  -USER_SIZE:<double>	Cellsize
	Floating point
	Minimum: 0.000000
	Default: 1.000000
  -USER_XMIN:<double>	West
	Floating point
	Default: 0.000000
  -USER_XMAX:<double>	East
	Floating point
	Default: 100.000000
  -USER_YMIN:<double>	South
	Floating point
	Default: 0.000000
  -USER_YMAX:<double>	North
	Floating point
	Default: 100.000000
  -USER_COLS:<num>   	Columns
	Integer
	Minimum: 1
	Default: 100
  -USER_ROWS:<num>   	Rows
	Integer
	Minimum: 1
	Default: 100
  -USER_FITS:<str>   	Fit
	Choice
	Available Choices:
	[0] nodes
	[1] cells
	Default: 0
  -TEMPLATE:<str>    	Target System
	Grid (optional input)
  -OUT_GRID:<str>    	Fractal Brownian Noise
	Grid (output)
  -SCALING:<str>     	Scaling
	Choice
	Available Choices:
	[0] linear
	[1] geometric
	Default: 1
  -MAX_SCALE:<double>	Maximum Scale
	Floating point
	Minimum: 0.000000
	Default: 1.000000
  -STEPS:<num>       	Steps
	Integer
	Minimum: 1
	Default: 8
  -RANGE_MIN:<double>	Noise Range
	Value range
  -RANGE_MAX:<double>	Noise Range
	Value range