rwGridsearch: Grid search optimization for random walk runout path

In jngtz/runout.opt: GPP regional runout model optimization and validation in R

Description

Computes the area under the receiver operating characteristic curve (AUROC) for runout paths simuluated using the random walk model component of the GPP tool in SAGA-GIS. The AUROC compares a runout polygon to the simulated path.

Usage

rwGridsearch(
  dem,
  slide_plys,
  slide_src,
  slide_id = NULL,
  slp_v,
  ex_v,
  per_v,
  gpp_iter = 1000,
  buffer_ext = 500,
  buffer_source = NULL,
  save_res = FALSE,
  plot_eval = FALSE,
  saga_lib
)

Arguments

dem	A DEM as a RasterLayer object
slide_plys	Runout tracks as a SpatialPolygonsDataFrame
slide_src	SSource points as a SpatialPointsDataFrame or source areas as a SpatialPolygonsDataFrame
slide_id	Selects a single runout polygon from slide_plys by row
slp_v	A vector of random walk slope thresholds - below lateral spreading is modeled
ex_v	A vector or random walk exponents controlling lateral spread
per_v	A vector or random walk persistence factors to weight flow direction consistency
gpp_iter	Number of model iterations
buffer_ext	(Optional) Defines buffer distance (in meters) around runout polygon to crop source DEM. This helps to reduce computational time
buffer_source	(Optional) Can define a buffer distance (in meters) to extend source point to a source area
save_res	(logical), if TRUE, will save results in current working directory
plot_eval	If TRUE, will plot random walk path and runout polygon
saga_lib	The initiated SAGA-GIS geoprocessor object

Details

Runout is either simulated from a single source point or a buffered area round the source point.

Value

the area under the receiver operating characteristic

jngtz/runout.opt documentation built on Sept. 8, 2021, 2:15 p.m.