Module Multiple Regression Analysis (Grid and Predictor Grids)
Linear regression analysis of one grid as dependent and multiple grids as indepentent (predictor) variables. Details of the regression/correlation analysis will be saved to a table. Optionally the regression model is used to create a new grid with regression based values. The multiple regression analysis uses a forward selection procedure. 
Reference:
- Bahrenberg, G., Giese, E., Nipper, J. (1992): 'Statistische Methoden in der Geographie 2 - Multivariate Statistik', Stuttgart, 415p.
- Author: O.Conrad (c) 2011
 
- Specification: grid
 
- Menu: Spatial and Geostatistics|Regression
 
Parameters
|   | Name | Type | Identifier | Description | Constraints | 
| Input | Dependent Variable | Grid (input) | DEPENDENT | - | - | 
 | Predictors | Grid list (input) | PREDICTORS | - | - | 
| Output | Regression | Grid (output) | REGRESSION | - | - | 
 | Residuals (*) | Grid (optional output) | RESIDUALS | - | - | 
 | Details: Coefficients (*) | Table (optional output) | INFO_COEFF | - | - | 
 | Details: Model (*) | Table (optional output) | INFO_MODEL | - | - | 
 | Details: Steps (*) | Table (optional output) | INFO_STEPS | - | - | 
| Options | Grid Interpolation | Choice | INTERPOL | - | Available Choices: [0] Nearest Neighbor [1] Bilinear Interpolation [2] Inverse Distance Interpolation [3] Bicubic Spline Interpolation [4] B-Spline Interpolation Default: 4 | 
 | Include X Coordinate | Boolean | COORD_X | - | Default: 0 | 
 | Include Y Coordinate | Boolean | COORD_Y | - | Default: 0 | 
 | Method | Choice | METHOD | - | Available Choices: [0] include all [1] forward [2] backward [3] stepwise Default: 3 | 
 | Significance Level | Floating point | P_VALUE | Significance level (aka p-value) as threshold for automated predictor selection, given as percentage | Minimum: 0.000000 Maximum: 100.000000 Default: 5.000000 | 
 | Cross Validation | Choice | CROSSVAL | - | Available Choices: [0] none [1] leave one out [2] 2-fold [3] k-fold Default: 0 | 
 | Cross Validation Subsamples | Integer | CROSSVAL_K | number of subsamples for k-fold cross validation | Minimum: 2 Default: 10 | 
| (*) optional | 
Command-line
Usage: saga_cmd statistics_regression 8 -DEPENDENT <str> -PREDICTORS <str> [-REGRESSION <str>] [-RESIDUALS <str>] [-INFO_COEFF <str>] [-INFO_MODEL <str>] [-INFO_STEPS <str>] [-INTERPOL <str>] [-COORD_X <str>] [-COORD_Y <str>] [-METHOD <str>] [-P_VALUE <str>] [-CROSSVAL <str>] [-CROSSVAL_K <num>]
  -DEPENDENT:<str> 	Dependent Variable
	Grid (input)
  -PREDICTORS:<str>	Predictors
	Grid list (input)
  -REGRESSION:<str>	Regression
	Grid (output)
  -RESIDUALS:<str> 	Residuals
	Grid (optional output)
  -INFO_COEFF:<str>	Details: Coefficients
	Table (optional output)
  -INFO_MODEL:<str>	Details: Model
	Table (optional output)
  -INFO_STEPS:<str>	Details: Steps
	Table (optional output)
  -INTERPOL:<str>  	Grid Interpolation
	Choice
	Available Choices:
	[0] Nearest Neighbor
	[1] Bilinear Interpolation
	[2] Inverse Distance Interpolation
	[3] Bicubic Spline Interpolation
	[4] B-Spline Interpolation
	Default: 4
  -COORD_X:<str>   	Include X Coordinate
	Boolean
	Default: 0
  -COORD_Y:<str>   	Include Y Coordinate
	Boolean
	Default: 0
  -METHOD:<str>    	Method
	Choice
	Available Choices:
	[0] include all
	[1] forward
	[2] backward
	[3] stepwise
	Default: 3
  -P_VALUE:<str>   	Significance Level
	Floating point
	Minimum: 0.000000
	Maximum: 100.000000
	Default: 5.000000
  -CROSSVAL:<str>  	Cross Validation
	Choice
	Available Choices:
	[0] none
	[1] leave one out
	[2] 2-fold
	[3] k-fold
	Default: 0
  -CROSSVAL_K:<num>	Cross Validation Subsamples
	Integer
	Minimum: 2
	Default: 10