On 5/3/2011 1:04 AM, Stefan Behnel wrote:
The bad thing about this recipe is that it requires quite a bit of background knowledge in order to infer that the code the developer is looking at is actually correct.
The main math knowledge needed is the trivial fact that if a*x + b = 0, then x = -b/a. The other math knowledge needed is that complex numbers add componentwise. The trick is that replacing x with j and evaluating therefore causes (in Python) all the coefficients of x (now j) to be added together separately from all the constant terms to reduce the linear equation to a*x+b (= 0 implied).
-- Terry Jan Reedy -- http://mail.python.org/mailman/listinfo/python-list
