pmml (version 1.3)

fileToXMLNode: Reads in a file and tries to parse it into an object of type XMLNode

Description

This function can be used when the user wants to read in an external file and convert it into an XMLNode to be used subsequently by other R functions.

Usage

fileToXMLNode(file)

Arguments

file

the external file to be read in. This file can be any file in PMML format, regardless of the source or model type.

Value

• An object of class XMLNode as that defined by the XML package. This represents the top level, or root node, of the XML document and is of type PMML. It can be written to file with saveXML.

Details

This function reads in a file and attempts to parse it into an XML node. This format is the one that will be obtained when a model is constructed in R and output in PMML format.

This function is mainly meant to be used to read in external files instead of depending on models saved in R. As an example, the pmml package requires as input an object of type XMLNode before its functions can be applied. Function 'fileToXMLNode' can be used to read in an existing PMML file, convert it to an XML node and then make it available for use by any of the pmml functions.

The 'addLT' function in this package details a scenario where one needs data transformations represented as part of the PMML file. This information is not necessarily in R since it may be stored externally in a PMML file. The example depicted here shows how one can import this file as a PMML object so it can be used as an input to the 'pmml' function which will in turn add it to a PMML model.

References

PMML home page: http://www.dmg.org

A. Guazzelli, W. Lin, T. Jena (2012), PMML in Action: Unleashing the Power of Open Standards for Data Mining and Predictive Analytics. CreativeSpace (Second Edition - Available on Amazon.com - http://www.amazon.com/dp/1470003244.

A. Guazzelli, M. Zeller, W. Lin, G. Williams (2009), PMML: An Open Standard for Sharing Models. The R journal, Volume 1/1, 60-65

See Also

pmml.

Examples

# define some transformations
library(pmml)
library(pmmlTransformations)

irisBox <- WrapData(iris)
irisBox <- ZScoreXform(irisBox,xformInfo = "column1->d1")
irisBox <- ZScoreXform(irisBox,xformInfo = "column2->d2")

#make a LocalTransformations element and save it to an external file
pmml_trans <- pmml(NULL, transforms=irisBox)
write(toString(pmml_trans),file = "xform_iris.pmml")

# Later, we may need to read in the PMML model into R
# 'lt' below is now a XML Node, as opposed to a string

lt <- fileToXMLNode("xform_iris.pmml")