function spectrum = nsplaplacian(g,m)
% This function computes the Neumann spectrum of the conformal
% laplacian with factor g
% size of g = 3^(m+1)

M = mlaplacian(g,m) ;

indices = singleindices(1:3^(m+1)) ;
M = M(indices,indices) ;

spectrum = eig(M) ;