# 'cstrt_regular_ngon' provides the vertices coordinates (a,b) of the
# regular small n-gon
function cstrt_regular_ngon(n)
if n >= 3
    a = zeros(n-1); b = zeros(n-1);
    if mod(n,2) == 1
        for i = 1:n-1
            a[i] = sin(2*pi*i/n)/(2*cos(pi/(2*n)));
            b[i] = (1 - cos(2*pi*i/n))/(2*cos(pi/(2*n)));
        end
    else
        for i = 1:n-1
            a[i] = sin(2*pi*i/n)/2;
            b[i] = (1 - cos(2*pi*i/n))/2;
        end
    end
    return(a,b)
end
end