Tom Johnson wrote:

What is the meaning of numpy's maximum on a complex-valued array?

We impose a lexicographical ordering on the complex space. Complex numbers are compared first by their real component and then, if the real components are equal, by their imaginary component. In [1]: from numpy import * In [19]: c = random.randint(0, 5, 10) + random.random(10)*1j In [20]: c Out[20]: array([ 0.+0.68448275j, 1.+0.97849291j, 3.+0.22114928j, 4.+0.65409519j, 3.+0.91550523j, 4.+0.50667105j, 1.+0.34576644j, 4.+0.97286048j, 1.+0.07268317j, 0.+0.52885086j]) In [21]: c.sort() In [22]: c Out[22]: array([ 0.+0.52885086j, 0.+0.68448275j, 1.+0.07268317j, 1.+0.34576644j, 1.+0.97849291j, 3.+0.22114928j, 3.+0.91550523j, 4.+0.50667105j, 4.+0.65409519j, 4.+0.97286048j]) -- Robert Kern "I have come to believe that the whole world is an enigma, a harmless enigma that is made terrible by our own mad attempt to interpret it as though it had an underlying truth." -- Umberto Eco