преобразование 1D массива в верхний треугольный
In [680]: ind = np.triu_indices(4)
In [681]: values = np.arange(16).reshape(4,4)[ind]
In [682]: result = np.zeros((4,4),int)
In [683]: result[ind]=values
In [684]: values
Out[684]: array([ 0, 1, 2, 3, 5, 6, 7, 10, 11, 15])
In [685]: result
Out[685]:
array([[ 0, 1, 2, 3],
[ 0, 5, 6, 7],
[ 0, 0, 10, 11],
[ 0, 0, 0, 15]])
Real Raccoon