# hdist: Geographical distance between catchments In transfR: Transfer of Hydrograph from Gauged to Ungauged Catchments

## Description

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

## Usage

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25``` ```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 \insertCiteGhosh1951;textualtransfR as proposed by \insertCiteGottschalk1993,Gottschalk2011;textualtransfR. The rescaled Ghosh distance (`method` "rghosh") is calculted following \insertCitedeLavenne2016;textualtransfR.

## Value

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

## References

\insertRef

Ghosh1951transfR

\insertRef

Gottschalk1993transfR

\insertRef

Gottschalk2011transfR

\insertRef

deLavenne2016transfR

## Examples

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

transfR documentation built on Sept. 8, 2021, 9:08 a.m.