hdist {transfR}

Geographical distance between catchments

Description

Calculate distances between two sets of catchments using their spatial support.

Usage

hdist(x, y, ...)

## S3 method for class 'sfc'
hdist(
  x,
  y,
  method = "rghosh",
  gres = 5,
  ditself = FALSE,
  maxsample = 25000,
  proj = NULL,
  parallel = FALSE,
  cores = NULL,
  verbose = TRUE,
  ...
)

## S3 method for class 'sf'
hdist(x, y, ...)

## S3 method for class 'stars'
hdist(x, y, ...)

## S3 method for class 'transfR'
hdist(x, y, method = "rghosh", weightO = 0.8, weightC = 0.2, ...)

Arguments

x

sf, stars or transfR object of the first catchments

y

sf, stars or transfR object of the second catchments

...

further arguments passed to or from other methods

method

the method to use for computing distance. This must be one of "ghosh", "rghosh", "points", "centroids", "combined"

gres

resolution of spatial discretisation (number of points by km²) for Ghosh distance

ditself

logical value indicating if the distance to itself should be computed. It will add one row and one column in the distance matrix. Only used if method is "ghosh"

maxsample

maximum size of sampling points for each catchments during spatial discretisation

proj

logical indicating if spatial layer are using a projection. If TRUE, euclidean distance is used. If FALSE, the great-circle distance is used

parallel

logical indicating if the computation should be parallelised

cores

the number of cores to use for parallel execution if parallel is TRUE. If not specified, the number of cores is set to the value of parallel::detectCores()

verbose

boolean indicating if information messages should be written to the console

weightO

weight given to the distance between outlets if method is "combined"

weightC

weight given to the distance between centroids if method is "combined"

Details

The method "ghosh" refers to a simplification of the distance defined by Ghosh (1951) as proposed by Gottschalk (1993); Gottschalk et al. (2011). The rescaled Ghosh distance (method "rghosh") is calculted following de Lavenne et al. (2016).

Value

A matrix of class units with the catchments of x organised in rows and the catchments of y organised in columns.

References

Ghosh B (1951). “Random distances within a rectangle and between two rectangles.” Bull. Calcutta Math. Soc, 43(1), 17–24.

Gottschalk L (1993). “Interpolation of runoff applying objective methods.” Stochastic Hydrology and Hydraulics, 7(4), 269–281. doi:10.1007/BF01581615.

Gottschalk L, Leblois E, Skøien JO (2011). “Distance measures for hydrological data having a support.” J. Hydrol., 402(3-4), 415–421. doi:10.1016/j.jhydrol.2011.03.020.

de Lavenne A, Skøien JO, Cudennec C, Curie F, Moatar F (2016). “Transferring measured discharge time series: Large-scale comparison of Top-kriging to geomorphology-based inverse modeling.” Water Resources Research, 52(7), 5555–5576. doi:10.1002/2016WR018716.

Examples

data(Oudon)
catchments <- st_geometry(Oudon$obs)
hdist(x = catchments[1:2], y = catchments[3:5], gres = 5, method = "rghosh")