# Main function for xgboost-package

xgboost = function(data=NULL, label = NULL, params=list(), nrounds=10, 
                   verbose = 1, ...)
{
    inClass = class(data)
    if (inClass=='dgCMatrix' || inClass=='matrix')
    {
        if (is.null(label))
            stop('xgboost: need label when data is a matrix')
        dtrain = xgb.DMatrix(data, label=y)
    }
    else
    {
        if (!is.null(label))
            warning('xgboost: label will be ignored.')
        if (inClass=='character')
            dtrain = xgb.DMatrix(data)
        else if (inClass=='xgb.DMatrix')
            dtrain = data
        else
            stop('xgboost: Invalid input of data')
    }
    
    if (verbose>1)
        silent = 0
    else
        silent = 1
    
    params = append(params, list(silent=silent))
    params = append(params, list(...)) 
    
    if (verbose>0)
        watchlist = list(train=dtrain)
    else
        watchlist = list()
    
    bst <- xgb.train(params, dtrain, nrounds, watchlist)
    
    return(bst)
}