getn()

function n=getn(psi,f)

Input:

• psi: sample values of $N_s$ orthonormal wave functions
• f: $Ns \times 1$ column vector of fillings

Output:

• n: sample values of electron density, $n_i=\sum_k f_k \psi_{ik}^* \psi_{ik}$

Modify getn() to accept a vector $\vec f$ of fillings as above and to compute the appropriate sum to form the density.