The glmnet package expects the input and predicted values in a matrix
format; they cannot be used as arrays or data frames. As of now, it
will also accept numerical values only. As such, any string variables
must be converted to numerical ones. One possible way to do so is to
use data transformation functions, such as from the 'pmmlTransformations'
package. However the result is a data frame. In all cases, lists, arrays
and data frames can be converted to a matrix format using the data.matrix
function from the base package. Given a data frame df, a matrix m can
thus be created by using m <- data.matrix(df). The PMML language requires variable names which will be read in as the
column names of the input matrix. If the matrix does not have variable
names, they will be given the default values of "X1", "X2", ...
PMML is an XML based language which
provides a way for applications to define statistical and data mining
models and to share models between PMML compliant applications. More
information about PMML and the Data Mining Group can be found at
http://www.dmg.org.
Use of PMML and pmml.cv.glmnet
requires the XML package. Be
aware that XML is a very verbose data format.
This function is used to export the structure of a general regression
model to any PMML consuming applications, such as the Zementis ADAPA and UPPI
scoring engines which allow for predictive models built in R to be deployed and
executed on site, in the cloud (Amazon, IBM, and FICO), in-database (IBM Netezza,
Pivotal, Sybase IQ, Teradata and Teradata Aster) or Hadoop (Datameer and Hive).