private static int expandSparseVector()

in flink-ml-lib/src/main/java/org/apache/flink/ml/feature/polynomialexpansion/PolynomialExpansion.java [244:288]
44 lines of code
6 McCabe index (conditional complexity)

        private static int expandSparseVector(
                int[] indices,
                double[] values,
                int lastIdx,
                int lastFeatureIdx,
                int degree,
                double factor,
                Tuple2<Integer, int[]> polyIndices,
                Tuple2<Integer, double[]> polyValues,
                int curPolyIdx) {
            if (!Double.valueOf(factor).equals(0.0)) {
                if (degree == 0 || lastIdx < 0) {
                    if (curPolyIdx >= 0) {
                        polyIndices.f1[polyIndices.f0] = curPolyIdx;
                        polyValues.f1[polyValues.f0] = factor;
                        polyIndices.f0++;
                        polyValues.f0++;
                    }
                } else {
                    double v = values[lastIdx];
                    int lastIdx1 = lastIdx - 1;
                    int lastFeatureIdx1 = indices[lastIdx] - 1;
                    double alpha = factor;
                    int curStart = curPolyIdx;
                    int i = 0;

                    while (i <= degree && Math.abs(alpha) > 0.0) {
                        curStart =
                                expandSparseVector(
                                        indices,
                                        values,
                                        lastIdx1,
                                        lastFeatureIdx1,
                                        degree - i,
                                        alpha,
                                        polyIndices,
                                        polyValues,
                                        curStart);
                        i++;
                        alpha *= v;
                    }
                }
            }
            return curPolyIdx + getResultVectorSize(lastFeatureIdx + 1, degree);
        }