[R] Refactor field logic for dmatrix (#9901)

R-package/man/setinfo.Rd

@@ -12,7 +12,7 @@ setinfo(object, ...)
 \arguments{
 \item{object}{Object of class "xgb.DMatrix"}
 
-\item{...}{other parameters}
+\item{...}{Not used.}
 
 \item{name}{the name of the field to get}
 

R-package/man/xgb.DMatrix.hasinfo.Rd

@@ -0,0 +1,32 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/xgb.DMatrix.R
+\name{xgb.DMatrix.hasinfo}
+\alias{xgb.DMatrix.hasinfo}
+\title{Check whether DMatrix object has a field}
+\usage{
+xgb.DMatrix.hasinfo(object, info)
+}
+\arguments{
+\item{object}{The DMatrix object to check for the given \code{info} field.}
+
+\item{info}{The field to check for presence or absence in \code{object}.}
+}
+\description{
+Checks whether an xgb.DMatrix object has a given field assigned to
+it, such as weights, labels, etc.
+}
+\examples{
+library(xgboost)
+x <- matrix(1:10, nrow = 5)
+dm <- xgb.DMatrix(x, nthread = 1)
+
+# 'dm' so far doesn't have any fields set
+xgb.DMatrix.hasinfo(dm, "label")
+
+# Fields can be added after construction
+setinfo(dm, "label", 1:5)
+xgb.DMatrix.hasinfo(dm, "label")
+}
+\seealso{
+\link{xgb.DMatrix}, \link{getinfo.xgb.DMatrix}, \link{setinfo.xgb.DMatrix}
+}