@Test public void testSubVectors() {
double[] data=new double[100];
for (int i=0; i<100; i++) data[i]=i;
ArraySubVector v=ArraySubVector.wrap(data);
assertEquals(10,v.get(10),0.0);
assertTrue(v.isView());
AVector v2=v.subVector(5, 90);
assertEquals(90,v2.length());
assertEquals(15,v2.get(10),0.0);
assertTrue(v2.isView());
AVector v3=v2.subVector(5,80);
assertEquals(20,v3.get(10),0.0);
assertTrue(v3.isView());
v3.set(10, -99);
assertEquals(-99,v.get(20),0.0);
}