deterministic

问题 Related to this question, I decided to check the UDFs in my data warehouse (which should largely have been deterministic), and I found several which aren't which should be. For instance: CREATE FUNCTION [udf_YearFromDataDtID] ( @DATA_DT_ID int ) RETURNS int AS BEGIN RETURN @DATA_DT_ID / 10000 END Shows up in this query: SELECT ROUTINE_NAME FROM INFORMATION_SCHEMA.ROUTINES WHERE IS_DETERMINISTIC = 'NO' AND ROUTINE_TYPE = 'FUNCTION' ORDER BY ROUTINE_NAME Why is this? 回答1: Yikes - apparently, it

问题 I'm using QueryPerformanceCounter to do some timing in my application. However, after running it for a few days the application seems to stop functioning properly. If I simply restart the application it starts working again. This makes me a believe I have an overflow problem in my timing code. // Author: Ryan M. Geiss // http://www.geisswerks.com/ryan/FAQS/timing.html class timer { public: timer() { QueryPerformanceFrequency(&freq_); QueryPerformanceCounter(&time_); } void tick(double

问题 I got confused with a seemingly simple concept. Mysql defines deterministic function as a function that always produces the same result for the same input parameters So in my understanding, functions like CREATE FUNCTION foo (val INT) READS SQL DATA BEGIN DECLARE retval INT; SET retval = (SELECT COUNT(*) FROM table_1 WHERE field_1 = val); RETURN retval; END; are not deterministic (there is no guarantee that delete/update/insert does not happen between 2 calls to the function). At the same

问题 So from what I understand about deterministic predicates: Deterministic predicate = 1 solution Non-deterministic predicate = multiple solutions Are there any type of rules as to how you can detect if the predicate is one or the other? Like looking at the search tree, etc. 回答1: There is no clear, generally accepted consensus about these notions. However, they are usually based rather on the observed answers and not based on the number of solutions. In certain contexts the notions are very

问题 I work in a very regulated environment where we need to be able to produce identical binary input give the same source code every time be build out products. We currently use an ancient version of g++ that has been patched to not write anything like a date/time in the resulting binaries that would change from build to build, but I would like to update to g++ 4.7.2. Does anyone know of a patch, or have suggestions of what I need to look for to take two identical pieces of source code and

问题 How do you say δ: Q × Σ → Q in English? Describing what × and → mean would also help. 回答1: δ is like a mathematical function called the transition function . Something like. z = f(x, y) A function in mathematical defines mapping of elements in one set to another set. In function set of input arguments are called Domain of a function and output is the rage. [ANSWER] In expression "δ:Q×Σ → Q" , × means Cartesian product (that is a set), and → is a mapping . "δ:Q×Σ → Q" says δ is a transition

问题 I've done some searching and I think the following code is guaranteed to produce output: B.X = 7 B.X = 0 A.X = 1 A = 1, B = 0 static class B { public static int X = 7; static B() { Console.WriteLine("B.X = " + X); X = A.X; Console.WriteLine("B.X = " + X); } } static class A { public static int X = B.X + 1; static A() { Console.WriteLine("A.X = " + X); } } static class Program { static void Main() { Console.WriteLine("A = {0}, B = {1}", A.X, B.X); } } I've run this numerous times and always

问题 Why this is non-deterministic and how to fix it? <xs:element name="activeyears"> <xs:complexType> <xs:sequence minOccurs="0" maxOccurs="1"> <xs:sequence minOccurs="0" maxOccurs="unbounded"> <xs:element ref="from" minOccurs="1" maxOccurs="1"/> <xs:element ref="till" minOccurs="1" maxOccurs="1"/> </xs:sequence> <xs:element ref="from" minOccurs="0" maxOccurs="1"/> </xs:sequence> </xs:complexType> </xs:element> It is supposed to mean that <activeyears> is either empty or contains sequence of

问题 I am student and in my programming course we have to learn Haskell. So I am new to it and i don't have that much experience. Also I am not familiar with posting questions in a forum. So first of all I will post the library, I have to work with. (DA : Deterministic Automaton) type State = Integer type DA = (State, State -> Char -> State, State -> Bool) type ListDA = (State, [((State, Char), State)], [State]) a :: DA a = (0, delta, (==1)) where delta 0 'a' = 1 delta 1 'a' = 1 delta 2 'a' = 1

问题 It seems like Box2D for actionscript 3 is not deterministic, it means, in the event of a multiplayer game wheere physics plays an important role in determining who wins/loses, the results would be different for each user if their microprocesors are from different technologies (intel and amd for example). So, is there a way to implement deterministic physics in AS3?, was this achieved before?. Thanks. 回答1: I once had this problem. We used Havok engine in Shockwave Director to simulate a