y.
The vector data is not necessarily stored contiguously; the
spacing between vector elements can be obtained via the stride()
member function.  Here is an example:
<pre>
Vector&lt;float&gt; x(10,0,1);          // Creates [ 0 1 2 3 4 5 6 7 8 9 ]
float* xptr = x.data();           // Get a pointer to the vector data
int length = x.length();          // Obtain the length of the vector (10)
int stride = x.stride();          // Note that stride may be negative

for (int i=0; i < length; ++i)
    xptr[i * stride