textureFlow: Calculation of textural features in flow direction

In ggRaver/Lslide: Functions for object-oriented image analysis in landslide science

Calculation of textural features in flow direction

Description

This function calculates textural features in flow direction according to STUMPF & KERLE (2011)

Usage

textureFlow(grass.texture.flowDir, grass.texture.input,
  saga.texture.shape = NULL, saga.texture.statistic = NULL,
  grass.texture.window = 3, quiet = TRUE,
  show.output.on.console = FALSE, grass.texture.distance = 1,
  grass.texture.method = "contrast,corr,var,sa,entr",
  grass.texture.name = c("_Contr_", "_Corr_", "_Var_", "_SA_", "_Entr_"),
  grass.categories.rules = "rules_texture", grass.texture.save = FALSE,
  grass.texture.save.path = tempdir(),
  texture.output.name = c("textureFlowDir", "textureFlowDirPer"))

Arguments

grass.texture.flowDir	full path to flow direction raster which must be performed by the D-Infinity method of TauDEM. Moreover, the angles must be in degree and already rotated (clockwise, NORTH 0°)
grass.texture.input	GRASS GIS raster on which the textural features are computed (commonly a DTM). Therefore, the input must be already imported or created in GRASS GIS
saga.texture.shape	full path of shapefile for the computation of grid statistics. Default: NULL
saga.texture.statistic	full storing path of shapefile with object statistics. Default: NULL
grass.texture.window	window size for the computation of textural features. Default: 3
quiet	no outputs in console. Default: TRUE
show.output.on.console	show output of GRASS and SAGA GIS modules on console. Default: FALSE
grass.texture.distance	distance between two samples. The distance must be smaller than the size of the moving window (>= 1). Default: 1
grass.texture.method	the textural features that the user wants to compute. Default: "contrast,corr,var,sa,entr"
grass.texture.name	name of texture for automatism. Number and names must fit to grass.texture.method. Default: c("_Contr_", "_Corr_", "_VAR_", "_SA_", "_Entr_")
grass.categories.rules	full stroing path of ruleset for reclassification of TauDEM flow direction. Default: tempdir() + rules_texture
grass.texture.save	possibility to save texture in flow direction as .tif. Default: FALSE (tif's are removed at the end)
grass.texture.save.path	(optional) output path of texture calculated in flow direction. Outputs are in .tif format. Default: tempdir()
texture.output.name	vector containing names for texture output, [1] for flow direction, [2] for perpendicular flow direction. Information on window size is automatically added after "_". Default: c("textureFlowDir", "textureFlowDirPer")
grass.texture.statistics	.csv with shapefile attributes including texture statistics

Value

(optional) data.table with texture statistics of shapefile input

Note

• the textural features MOC-1 and MOC-2 are not supported, yet

• calculation of textures is for all directions separately

• GRASS GIS session (mapset, location and raster for texture) must have been initialized before

• GRASS GIS texture orientations are counter-clockwise beginning from EAST, but output is calculated clockwise beginning from NORTH

• TO DO: ratio of texture in flow direction to texture in perpendicular flow direction

• STUMPF, A. & N. KERLE (2011): Object-oriented mapping of landslides using Random Forests. - Remote Sensing of Environment 115, 10, 2564-2577

ggRaver/Lslide documentation built on April 8, 2022, 7:14 a.m.