ds.asNumeric.RdCoerces an R object into a numeric class.
This function is based on the native R function as.numeric.
ds.asNumeric(x.name = NULL, newobj = NULL, datasources = NULL)a character string providing the name of the input object to be coerced to a numeric.
a character string that provides the name for the output object
that is stored on the data servers. Default asnumeric.newobj.
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.
ds.asNumeric returns the R object converted into a numeric class
that is written to the server-side. Also, two validity messages are returned
to the client-side indicating the name of the newobj which
has been created in each data source and if
it is in a valid form.
This function is based on the native R function as.numeric.
However, it behaves differently with some specific classes of variables. For example, if the input
object is of class factor, it first converts its values into characters and then convert those to
numerics. This behavior is important for the case where the input object is of class factor having
numbers as levels. In that case, the native R
as.numeric function returns the underlying level codes and not the values as numbers.
For example as.numeric in R converts the factor vector:
0 1 1 2 1 0 1 0 2 2 2 1
Levels: 0 1 2
to the following numeric vector:
1 2 2 3 2 1 2 1 3 3 3 2
In contrast DataSHIELD converts an input factor with numeric
levels to its original numeric values.
Server function called: asNumericDS
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()
connections <- DSI::datashield.login(logins = logindata, assign = TRUE, symbol = "D")
# Converting the R object into a numeric class
ds.asNumeric(x.name = "D$LAB_TSC",
newobj = "num.obj",
datasources = connections[1]) #only the first Opal server is used ("study1")
ds.class(x = "num.obj", datasources = connections[1])
# Clear the Datashield R sessions and logout
datashield.logout(connections)
} # }