SparseVector extends Vector { @Override public double normL2Square() { double d = 0; for (double t : values) { d += t * t; } return d; } SparseVector();  SparseVector(int n);  SparseVector(int n, int[] indices, double[] values);  SparseVector(int n, Map<Integer, Double> kv); @Override SparseVector clone(); @Override SparseVector prefix(double d); @Override SparseVector append(double d); int[] getIndices(); double[] getValues(); @Override int size(); @Override double get(int i); void setSize(int n); int numberOfValues(); @Override void set(int i, double val); @Override void add(int i, double val); @Override String toString(); @Override double normL2(); @Override double normL1(); @Override double normInf(); @Override double normL2Square(); @Override SparseVector slice(int[] indices); @Override Vector plus(Vector vec); @Override Vector minus(Vector vec); @Override SparseVector scale(double d); @Override void scaleEqual(double d); void removeZeroValues(); @Override double dot(Vector other); @Override DenseMatrix outer(); DenseMatrix outer(SparseVector other); DenseVector toDenseVector(); @Override void standardizeEqual(double mean, double stdvar); @Override void normalizeEqual(double p); @Override boolean equals(Object o); @Override int hashCode(); void forEach(BiConsumer<Integer, Double> action); @Override VectorIterator iterator();  }
@Test public void testNormL2Square() throws Exception { Assert.assertEquals(v2.normL2Square(), 3.0, TOL); }