\HeaderA{mlbench.circle}{Circle in a Square Problem}{mlbench.circle}
\keyword{datagen}{mlbench.circle}
\begin{Description}\relax
The inputs of the circle problem are uniformly distributed on
the \code{d}-dimensional cube with corners \eqn{\{\pm 1\}}{\{+-1\}}. 
This is a 2-class problem: The first class is a \code{d}-dimensional
ball in the middle of the cube, the remainder forms the second
class. The size of the ball is chosen such that both classes have equal
prior probability 0.5.
\end{Description}
\begin{Usage}
\begin{verbatim}
mlbench.circle(n, d=2)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{n}] number of patterns to create
\item[\code{d}] dimension of the circle problem
\end{ldescription}
\end{Arguments}
\begin{Value}
Returns an object of class \code{"mlbench.circle"}  with components
\begin{ldescription}
\item[\code{x}] input values
\item[\code{classes}] factor vector of length \code{n} with target classes
\end{ldescription}
\end{Value}
\begin{Examples}
\begin{ExampleCode}
# 2d example
p<-mlbench.circle(300,2)
plot(p)
#
# 3d example
p<-mlbench.circle(300,3)
plot(p)
\end{ExampleCode}
\end{Examples}

