@SuppressWarnings("null") private static void plotFeatures(Features feat, double[] xSamples) throws IOException { final int nbRBFFeat = feat.outDim; final int nbSamples = xSamples.length; @NonNull final double[][] yRBF = new double[nbSamples][nbRBFFeat]; final long startTime = System.currentTimeMillis(); for (int i = 0; i < nbSamples; i++) { @NonNull final double[] x = new double[] {xSamples[i]}; feat.phi(x, yRBF[i]); } final long endTime = System.currentTimeMillis(); System.out.println("Time elapsed : " + (endTime - startTime)); System.out.println(ArrUtils.toString(yRBF)); @NonNull final Plot2D plotRBF = new Plot2D(feat.toString(), "x", "y"); plotRBF.plot(xSamples, ArrUtils.transpose(yRBF, nbSamples, nbRBFFeat)[0]); }