[eigen] Eigen objects as vectors and matrices

[Brad Bell <bradbell@xxxxxxxxxx>]

I want to an object both as a matrix and as a vector, so I am 
constructing the object using
    Matrix<double, Dynamic, Dynamic> object(m*n, 1);
and then plan to do an
    object. conservativeResize(m, n)
before using it as a matrix. The problem is that the bracket operator
    object[i]
does not seem to work when object is a vector (and the software I am 
using access vectors this way).

For example, the following source code does not compile:

    # include <Eigen/Dense>
    int main(void)
    {
         using Eigen::Matrix;
         using Eigen::Dynamic;

         typedef Matrix<double, Dynamic, Dynamic> matrix;

         matrix v(2,1);
         v[0] = 1.0;
         v[1] = 2.0;

         return 0;
    }
~