NNS Term Matrix

Generates a term matrix for text classification use in NNS.reg.

Usage

NNS.term.matrix(x, oos = NULL)

Arguments

x

mixed data.frame; character/numeric; A two column dataset should be used. Concatenate text from original sources to comply with format. Also note the possibility of factors in "DV", so "as.numeric(as.character(...))" is used to avoid issues.

oos

mixed data.frame; character/numeric; Out-of-sample text dataset to be classified.

Value

Returns the text as independent variables "IV" and the classification as the dependent variable "DV". Out-of-sample independent variables are returned with "OOS".

References

Viole, F. and Nawrocki, D. (2013) "Nonlinear Nonparametric Statistics: Using Partial Moments" (ISBN: 1490523995)

Examples

if (FALSE) { # \dontrun{
x <- data.frame(cbind(c("sunny", "rainy"), c(1, -1)))
NNS.term.matrix(x)

### Concatenate Text with space separator, cbind with "DV"
x <- data.frame(cbind(c("sunny", "rainy"), c("windy", "cloudy"), c(1, -1)))
x <- data.frame(cbind(paste(x[ , 1], x[ , 2], sep = " "), as.numeric(as.character(x[ , 3]))))
NNS.term.matrix(x)

### NYT Example
require(RTextTools)
data(NYTimes)

### Concatenate Columns 3 and 4 containing text, with column 5 as DV
NYT <- data.frame(cbind(paste(NYTimes[ , 3], NYTimes[ , 4], sep = " "),
                     as.numeric(as.character(NYTimes[ , 5]))))
NNS.term.matrix(NYT)
} # }