title: diagonal matrix of a matrix with numpy and scipy
body: <p>I have a matrix (n*1) and I want to make a diagonal matrix with it.
  but I can't construct it with numpy.
  I tried each methods in numpy such as methods in <a href="http://wiki.scipy.org/NumPy_for_Matlab_Users#head-3ad4144208bdb8910ff1488c3e5bcd93e764dbc4" rel="nofollow">this</a></p>