infinity

问题 I am trying to understand floating point representations. I do not understand the 'infinity' 'NaN' representations in floating point. I am looking at the table provided by TopCoder. Infinity is represented by an exponent of all 1s and a Mantissa of all 0s. I can only read it as 0^n, and I'm not sure how that tends to infinity. 回答1: You should simply ignore the bit patterns used and treat infinities and NaNs as special values. Unless you do bit-fiddling on your floats (for which I see very

问题 It's the smallest I could find. 回答1: The JSON RFC ( http://tools.ietf.org/html/rfc4627 ) states that NaN, Positive Infinity and Negative Infinity cannot be represented in JSON: Numeric values that cannot be represented as sequences of digits (such as Infinity and NaN) are not permitted. I don't know where you're getting 1*10^309 from, because Javascript's maximum exact integer value is 2^53. When you say "concise" do you actually mean "succinct"? 来源： https://stackoverflow.com/questions

问题 I am reading about positive and negative infinity in c++. I read that integral types dont have a infinite value ie. std::numeric_limits<int>::infinity(); wont work, but std::numeric_limits<int>::max(); will work and will represent the maximum possible value that can be represented by the integral type. so the std::numeric_limits<int>::max(); of the integral type could be taken as its positive infinite limit ? Or the integral type has only the max value and the infinity value is not true ? 回答1

问题 double d=1/0.0; System.out.println(d); It prints Infinity , but if we will write double d=1/0; and print it we'll get this exception: Exception in thread "main" java.lang.ArithmeticException: / by zero at D.main(D.java:3) Why does Java know in one case that diving by zero is infinity but for the int 0 it is not defined? In both cases d is double and in both cases the result is infinity. 回答1: Floating point data types have a special value reserved to represent infinity, integer values do not.

问题 A NAN value means Not A Number and IND value means Indeterminate number. But what is the difference between these two. How can we represent both in c++. 回答1: But what is the difference between these two. They are both the same thing. Some platforms choose to display a non-number as some variant of NaN , while others choose to display it as some variant of IND . How can we represent both in c++. std::numeric_limits<double>::quiet_NaN() (or float or long double , if you prefer). 回答2: If your

问题 I'm looking over some complex Python 2.6 code which is occasionally resulting in an infinity being generated (at least an Infinity being serialized by the json library -- which checks w/ math.isinf). What is especially baffling is that Python (as far as I can tell) shouldn't be able to ever produce computation results set to infinity. Am I wrong with this assumption? I was aware you can only get infinities from constants: k = float('inf') k = 1e900 回答1: Somewhere between 1e308 and 1e309 the

问题 I'm caclulating the mean value of a function's request/sec, appearently the result number sometimes is too long so it displays as Infinity, is there a way to round it so it show a number only? Or make a sleep()/wait() while it's on Infinity? well to be exactly, im monitoring req/sec on a graph, when it's infinity the line goes up not towards zero 回答1: It's not too long to display. If you get Inf then you can't do anything with it other than know that it is something larger than the maximum

问题 I have come across with the following two codes. Why does it not throw an exception for floating point where as in other case it will throw a runtime exception. class FloatingPoint { public static void main(String [] args) { float a=1000f; float b=a/0; System.out.println("b=" +b); } } OUTPUT:b=Infinity . If I try with int values then it will throw a runtime exception. Why is it like this? 回答1: The short answer Integral types (JLS 4.2.1) are categorically different from floating point types

问题 Why is the Infinity property used as a command (rather than a result) For example, this code below works, but the result isn't what I expected. alert(isOdd(Infinity)); function isOdd(num) { return num%2==1; } 回答1: MDN REFERENCE Infinity is a property of the global object, i.e. it is a variable in global scope. The initial value of Infinity is Number.POSITIVE_INFINITY. The value Infinity (positive infinity) is greater than any other number. This value behaves mathematically like infinity; for

问题 Why is the Infinity property used as a command (rather than a result) For example, this code below works, but the result isn't what I expected. alert(isOdd(Infinity)); function isOdd(num) { return num%2==1; } 回答1: MDN REFERENCE Infinity is a property of the global object, i.e. it is a variable in global scope. The initial value of Infinity is Number.POSITIVE_INFINITY. The value Infinity (positive infinity) is greater than any other number. This value behaves mathematically like infinity; for