Read the *.dfn file, create the variables based on the info
The format of a *.dfn file is as follows:
field name type usage
field1 continuous input
field2 discrete input
field3 categorical output
dummy1 continuous ignore
dummy2 boolean ignore
where field name: must be a unique name
where type: is a valid Able data type (boolean, categorical, continuous, discrete, etc.)
where usage: indicates processing directives, input, output/target , or ignore
load the entire data file from a text file into a vector of String arrays
assumes the data file definition (variables) has already be loaded
text data can be accessed using getTextRecord()
numeric data can be accessed using getNumericRecord()
If "logger" is not null, ABLE base code will use the specified
logger's entry(), exit(), text(), and exception() methods to log
trace messages, but only if the logger's "isLogging" public
instance variable is set to true.