infinity

IEEE 754 specifies the result of 1 / 0 as ∞ (Infinity). However, IEEE 754 then specifies the result of 0 × ∞ as NaN. This feels counter-intuitive : Why is 0 × ∞ not 0? We can think of 1 / 0 = ∞ as the limit of 1 / z as z tends to zero We can think of 0 × ∞ = 0 as the limit of 0 × z as z tends to ∞. Why does the IEEE standard follow intuition 1. but not 2.? It is easier to understand the behavior of IEEE 754 floating point zeros and infinities if you do not think of them as being literally zero or infinite. The floating point zeros not only represent the real number zero. They also represent

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; } 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 example, any positive number multiplied by Infinity is Infinity, and anything divided by Infinity is 0.

Does GLSL have any pre-defined constants for +/-infinity or NaN? I'm doing this as a workaround but I wonder if there is a cleaner way: // GLSL FRAGMENT SHADER #version 410 <snip> const float infinity = 1. / 0.; void main () { <snip> } I am aware of the isinf function but I need to assign infinity to a variable so that does not help me. Jan Rüegg Like Nicol mentioned, there are no pre-defined constants. However, from OpenGL 4.1 on, your solution is at least guaranteed to work and correctly generate an infinite value. See for example in glsl 4.4 : 4.7.1 Range and Precision ... However, dividing

How can I represent -infinity in C++, Java, etc.? In my exercise, I need to initialize a variable with -infinity to show that it's a very small number. When computing -infinity - 3 , or -infinity + 5 it should also result -infinity . I tried initializing it with INT_MIN , but when I compute INT_MIN - 1 I get the upper limit, so I can't make a test like: if(value < INT_MIN) var = INT_MIN; So how can I do that? You could define a number as -infinite and, when adding or substracting something from a number, you do first check if the variable was equal to that pseudo-number. If so you just leave

What is the meaning of 'infinity' in PostgreSQL range types? Is there any difference between specifying infinity or -infinity as a bound, or NULL ? I.e. is infinity an explicit form of specifying that the range bound is infinite, whereas NULL would implicit specify an infinite bound range? See the following examples: SELECT tstzrange('-infinity','infinity') && tstzrange(NULL, NULL); ?column? ---------- t SELECT tstzrange('2013-01-01 00:00:00+01', '2013-02-01 00:00:00+01') && tstzrange(NULL, '2013-03-01 00:00:00+01'); ?column? ---------- t SELECT tstzrange('2013-01-01 00:00:00+01', '2013-02-01

So a quick thought; Could one argue that O(∞) is actually O(1)? I mean it isn't depend on input size? So in some way its, constant, even though it infinity. Or is the only 'correct' way to express it O(∞)? Infinity is not a number, or at least not a real number , so the expression is malformed. The correct way to express this is to simply state that a program doesn't terminate. Note: program , not algorithm , as an algorithm is guaranteed to terminate. (If you wanted, you might be able to define big-O notation on transfinite numbers. I'm not sure if that would be of any use, though.) Your