Generates a density grid in the client-side

This function generates a grid density object which can then be used to produced heatmap or contour plots.

ds.densityGrid(
  x = NULL,
  y = NULL,
  numints = 20,
  type = "combine",
  datasources = NULL
)

Arguments

x

a character string providing the name of the input numerical vector.

y

a character string providing the name of the input numerical vector.

numints

an integer, the number of intervals for the grid density object. The default value is 20.

type

a character string that represents the type of graph to display. If type is set to 'combine', a pooled grid density matrix is generated, instead if type is set to 'split' one grid density matrix is generated. Default 'combine'.

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.densityGrid returns a grid density matrix.

Details

The cells with a count > 0 and < nfilter.tab are considered invalid and the count is set to 0.

In DataSHIELD the user does not have access to the micro-data so and extreme values such as the maximum and the minimum are potentially non-disclosive so this function does not allow for the user to set the limits of the density grid and the minimum and maximum values of the x and y vectors. These elements are set by the server-side function densityGridDS to 'valid' values (i.e. values that do not lead to leakage of micro-data to the user).

Server function called: densityGridDS

Author

DataSHIELD Development Team

Examples

if (FALSE) { # \dontrun{

 ## Version 6, for version 5 see the Wiki
  # 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()
  
  # Log onto the remote Opal training servers
  connections <- DSI::datashield.login(logins = logindata, assign = TRUE, symbol = "D") 
 
  #Generate the density grid
  # Example1: generate a combined grid density object (default)
  ds.densityGrid(x="D$LAB_TSC",
                 y="D$LAB_HDL",
                 datasources = connections)#all opal servers are used

  # Example2: generate a grid density object for each study separately
  ds.densityGrid(x="D$LAB_TSC",
                 y="D$LAB_HDL",
                 type="split",
                 datasources = connections[1])#only the first Opal server is used ("study1")

  # Example3: generate a grid density object where the number of intervals is set to 15, for
  #           each study separately
  ds.densityGrid(x="D$LAB_TSC",
                 y="D$LAB_HDL",
                 type="split",
                 numints=15,
                 datasources = connections)

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

} # }