non-deterministic

I have a script which uses no randomisation that gives me different answers when I run it. I expect the answer to be the same, every time I run the script. The problem appears to only happen for certain (ill-conditioned) input data. The snippet comes from an algorithm to compute a specific type of controller for a linear system, and it mostly consists of doing linear algebra (matrix inversions, Riccati equation, eigenvalues). Obviously, this is a major worry for me, as I now cannot trust my code to give me the right results. I know the result can be wrong for poorly conditioned data, but I

Consider a function choose in Curry programming language with the specification that " (choose xs) non-deterministically chooses one element from the list xs ". I'd implement it straighforwardly through two alternative non-deterministic rules: choose :: [a] -> a choose x:_ = x choose _:xs = choose xs But in /usr/lib/curry-0.9.11/Success.curry from Muenster Curry Compiler , it is defined with a helper function: choose (x:xs) = choosep x xs where choosep x [] = x choosep x (_:_) = x choosep _ (x:xs) = choosep x xs What could be the advantages (if any) of the definition from the compiler supplied

When the code is waiting for some condition in which delay time is not deterministic, it looks like many people choose to use exponential backoff, i.e. wait N seconds, check if the condition satisfies; if not, wait for 2N seconds, check the condition, etc. What is the benefit of this over checking in a constant/linearly increasing time span? This is the behavior of TCP congestion control. If the network is extremely congested, effectively no traffic gets through. If every node waits for a constant time before checking, the traffic just for checking will continue to clog the network, and the

Closed. This question is off-topic. It is not currently accepting answers. Learn more . Want to improve this question? Update the question so it's on-topic for Stack Overflow. I do not the understand the concept of Non Deterministic Turing Machine . I guess I understand the term Non deterministic algorithm : (nondeterministic algorithm is an algorithm that can exhibit different behaviors on different runs, as opposed to a deterministic algorithm.) So the algorithm could be like : a = fromSomeAlgo(); if(a > foo) stateA(); else stateB(); But for non-deterministic turing machine I read , it can

Python 2 Sets are collections of unordered values. If I construct a set via a set literal, e.g. s = {'a', 'b', 'c'} and then print it, I get the elements in some scrambled order. However, it seems that in Python 2.7, the above example always results in the same ordering: print(s) # set(['a', 'c', 'b']) in Python 2.7 How does Python 2.7 decide on this ordering? Even the hashes of 'a' , 'b' and 'c' are not in the order produced. Python 3 In Python 3.x (including 3.6 where dict keys are ordered) the resulting order seems to be random, though always the same within a given Python process. That is,

I have the following code: import Control.Monad coin :: MonadPlus m => m Int coin = return 0 `mplus` return 1 If I evaluate coin :: Maybe Int on the interpreter, it prits Just 0 . That's normal because of the implementation of Maybe as instance of MonadPlus. If I evaluate coin :: [Int] on the interpreter, it prints [0, 1] , because the implementation of mplus on list is an append . But if I evaluate coin , without any type decorators, it prints 0 . Why? What type does the interpreter 'converts' coin to evaluate it? This code is extracted from: http://homes.sice.indiana.edu/ccshan/rational