Finds the existing SAGA GIS installation(s), generates and sets the necessary path and system variables for a seamless use of the command line calls of the 'SAGA GIS' CLI API, setup valid system variables for calling a default rsaga.env and by this makes available the RSAGA wrapper functions.
All existing installation(s) means that it looks for the saga_cmd or saga_cmd.exe executables. If the file is found it is assumed to be a valid 'SAGA GIS' installation. If it is called without any argument the most recent (i.e. highest) SAGA GIS version will be linked.

linkSAGA(
  default_SAGA = NULL,
  searchLocation = "default",
  ver_select = FALSE,
  quiet = TRUE,
  returnPaths = TRUE
)

Arguments

default_SAGA

string contains path to RSAGA binaries

searchLocation

drive letter to be searched, for Windows systems default is C:, for Linux systems default is /usr.

ver_select

boolean default is FALSE. If there is more than one 'SAGA GIS' installation and ver_select = TRUE the user can select interactively the preferred 'SAGA GIS' version

quiet

boolean switch for supressing console messages default is TRUE

returnPaths

boolean if set to FALSE the pathes of the selected version are written to the PATH variable only, otherwise all paths and versions of the installed SAGA versions ae returned.#'@details If called without any parameter linkSAGA() it performs a full search over C:. If it finds one or more 'SAGA GIS' binaries it will take the first hit. You have to set ver_select = TRUE for an interactive selection of the preferred version. Additionally the selected SAGA pathes are added to the environment and the global variables sagaPath, sagaModPath and sagaCmd will be created.

Value

A list containing the selected RSAGA path variables $sagaPath,$sagaModPath,$sagaCmd and potentially other installations $installed

Note

The excellent 'SAGA GIS' wrapper RSAGA package was updated several times however it covers currently (Dec 2019) only 'SAGA GIS' versions from 2.3.1 - 6.3.0 The fast evolution of 'SAGA GIS' makes it highly impracticable to keep the wrapper adaptions in line (currently 7.5). RSAGA will meet all linking needs perfectly if you use 'SAGA GIS' versions from 2.0.4 - 7.5.0.
However you must call rsaga.env using the rsaga.env(modules = saga$sagaModPath) assuming that saga contains the returnPaths of linkSAGA In addition most recently the very promising Rsagacmd wrapper package is providing a new list oriented wrapping tool.

Examples

if (FALSE) { # call if you do not have any idea if and where SAGA GIS is installed # it will return a list with the selected and available SAGA installations # it prepares the system for running the selected SAGA version via RSAGA or CLI linkSAGA() # overriding the default environment of rsaga.env call saga<-linkSAGA() if (saga$exist) { require(RSAGA) RSAGA::rsaga.env(path = saga$installed$binDir[1],modules = saga$installed$moduleDir[1]) } }