predict-GPC-method: Predict labels from unlabelled data.
In JimSkinner/gpclassifier: Implements a Gaussian Process binary Classifier

Use a trained GPC classifier to produce label predictions of a new set of unlabelled data.

1 2	## S4 method for signature 'GPC' predict(object, Xst)

`object`	A fitted GPC objet
`Xst`	A matrix of data for which to produce label predictions

# Create synthetic dataset
X <- matrix(rnorm(60), ncol=2)
Y <- rowSums(X^2) < 1

# New GPX Object with default squared exponential covariance function.
gpc <- GPC(X, Y)

# Predict labels for new data
Xst <- matrix(rnorm(60), ncol=2)
Yst <- predict(gpc, Xst)