6.2.1.2 Optional and Control Arguments

All of the embedded R execution functions take optional arguments, which can be named or not.

Oracle Machine Learning for R passes user-defined optional arguments to the input function. You can pass any number of optional arguments to the input function, including complex R objects such as models.

Arguments that start with ore. are special control arguments. OML4R does not pass them to the input function, but instead uses them to control what happens before or after the execution of that function. The following control arguments are supported:

• ore.connect controls whether to automatically connect to OML4R inside the embedded R execution function. This is equivalent to doing an ore.connect call with the same credentials as the client session. The default value is FALSE.

  If an automatic connection is enabled, the following functionality occurs:

  • The embedded R script is connected to the database.

  • The connection has the same credentials as the session that invokes the embedded R SQL function.

  • The script runs in an autonomous transaction.

  • ROracle queries can work with the automatic connection.

  • OML4R transparency layer functionality is enabled in the embedded script.

• ore.drop controls the input data. If the option value is TRUE, a one column data.frame is converted to a vector. The default value is TRUE.

• ore.envAsEmptyenv controls whether an environment referenced in an object is replaced with an empty environment during serialization. Some types of input parameters and returned objects, such as list and formula, are serialized before being saved to the database. If the control argument value is TRUE, then the referenced environment in the object is replaced with an empty environment whose parent is .GlobalEnv and the objects in the original referenced environment are not serialized. In some cases, this can significantly reduce the size of serialized objects. If the control argument value is FALSE, then all of the objects in the referenced environment are serialized and can be unserialized and recovered later. The default value is regulated by the global option ore.envAsEmptyenv.

• ore.na.omit controls the handling of missing values in the input data. If you specify ore.na.omit = TRUE, then rows or vector elements, depending on the ore.drop setting, that contain missing values are removed from the input data. If all of the rows in a chunk contain missing values, then the input data for that chunk will be an empty data.frame or vector. The default value is FALSE.

• ore.graphics controls whether to start a graphical driver and look for images. The default value is TRUE.

• ore.png.* specifies additional arguments for the png graphics driver if ore.graphics is TRUE. The naming convention for these arguments is to add an ore.png. prefix to the arguments of the png function. For example, if ore.png.height is supplied, argument height is passed to the png function. If not set, the standard default values for the png function are used.

See Also:

For more details about control arguments, see the online help displayed by invoking help(ore.doEval)