Example of how to build a DataSet from scratch about jsat HOT 2 CLOSED

    public static void main(String[] args)
    {
        //Some random data we want to convert to a DataSet object manually 
        Random rand = new XORWOW();
        double[][] someStuffIWantToMakeIntoADataSet = new double[20][6];
        for(int i = 0; i < someStuffIWantToMakeIntoADataSet.length; i++)
            for(int j = 0; j < someStuffIWantToMakeIntoADataSet[i].length; j++)
                someStuffIWantToMakeIntoADataSet[i][j] = rand.nextDouble();

        //Lets decide the first 2 features are categorical and the rest are just numeric

        //First we need the list the categories. Well create 1 categorie with 2 options and a 2nd category with 3 options. 
        CategoricalData[] categories = new CategoricalData[]
        {
            new CategoricalData(2), new CategoricalData(3)
        };

        SimpleDataSet sds = new SimpleDataSet(categories, 4);

        for(double[] row : someStuffIWantToMakeIntoADataSet)
        {
            //first a place to store the categorical values. 
            int[] catValues = new int[categories.length];
            catValues[0] =  (int) Math.round(row[0]);//first cat will be whether the value was closer to 0 or 1
            catValues[1] =  (int) Math.round(row[1]*2);//similar for second
            //Next we need a place to store the numeric features
            Vec numericValues = new DenseVector(4);
            for(int i = 0; i < 4; i++)
                numericValues.set(i, row[2+i]);
            DataPoint dp = new DataPoint(numericValues, catValues, categories);
            //now just add to the dataset
            sds.add(dp);
        }

        //done, we have made a data set
    }