>>> import numpy as np >>> x = 1 + 2 * 1j >>> C = np.zeros((2,2),dtype=np.complex_) >>> C array([[ 0.+0.j, 0.+0.j], [ 0.+0.j, 0.+0.j]]) >>> C[0,0] = 1+1j + x >>> C array([[ 2.+3.j, 0.+0.j], [ 0.+0.j, 0.+0.j]])