Perform 'unique' on a variable on the server-side

Perform 'unique', from the 'base' package on a specified variable on the server-side

ds.unique(x.name = NULL, newobj = NULL, datasources = NULL)

Arguments

x.name

a character string providing the name of the varable, in the server, to perform unique upon

newobj

a character string that provides the name for the output object that is stored on the data servers. Default unique.newobj.

datasources

a list of DSConnection-class objects obtained after login. If the datasources argument is not specified the default set of connections will be used: see datashield.connections_default.

Value

ds.unique returns the vector of unique R objects which are written to the server-side.

Details

Will create a vector or list which has no duplicate values.

Server function called: uniqueDS

Author

Stuart Wheater, DataSHIELD Development Team

Examples

if (FALSE) { # \dontrun{
  # connecting to the Opal servers

  require('DSI')
  require('DSOpal')
  require('dsBaseClient')

  builder <- DSI::newDSLoginBuilder()
  builder$append(server = "study1",
                 url = "http://192.168.56.100:8080/",
                 user = "administrator", password = "datashield_test&",
                 table = "CNSIM.CNSIM1", driver = "OpalDriver")
  builder$append(server = "study2",
                 url = "http://192.168.56.100:8080/",
                 user = "administrator", password = "datashield_test&",
                 table = "CNSIM.CNSIM2", driver = "OpalDriver")
  builder$append(server = "study3",
                 url = "http://192.168.56.100:8080/",
                 user = "administrator", password = "datashield_test&",
                 table = "CNSIM.CNSIM3", driver = "OpalDriver")
  logindata <- builder$build()

  connections <- DSI::datashield.login(logins = logindata, assign = TRUE, symbol = "D")

  # Create a vector with combined objects
  ds.unique(x.name = "D$LAB_TSC", newobj = "new.vect", datasources = connections)

  # Clear the Datashield R sessions and logout
  datashield.logout(connections)
} # }