Your reasoning is that Double.POSITIVE_INFINITY should not be equal to itself because it is “likely” to have been obtained as the result of a loss of accuracy. This line of reasoning applies to all of floating-point. Any finite value can be obtained as the result of an inaccurate operation. That did not push the IEEE … Read more
The free final draft of the C99 specification says on page 491 clog(+∞, +i∞) returns +∞ + iπ/4. This is still the case currently. The C++ specification explains the same rules with the note The semantics of this function are intended to be consistent with the C function clog. I agree the behaviour is confusing … Read more
Because that’s how floating-point is defined (more generally than just Javascript). See for example: http://en.wikipedia.org/wiki/Floating-point#Infinities http://en.wikipedia.org/wiki/NaN#Creation Crudely speaking, you could think of 1/0 as the limit of 1/x as x tends to zero (from the right). And 0/0 has no reasonable interpretation at all, hence NaN.
There is: from numpy import inf x[x == -inf] = 0
As of Swift 3+, you should use: CGFloat.greatestFiniteMagnitude Double.greatestFiniteMagnitude Float.greatestFiniteMagnitude
You are right that an integer infinity is possible, and that none has been added to the Python standard. This is probably because math.inf supplants it in almost all cases (as Martijn stated in his comment). In the meantime, I added an implementation of extended integers on PyPI: In [0]: from numbers import Integral, Real … Read more
if (result == Number.POSITIVE_INFINITY || result == Number.NEGATIVE_INFINITY) { // … } You could possibly use the isFinite function instead, depending on how you want to treat NaN. isFinite returns false if your number is POSITIVE_INFINITY, NEGATIVE_INFINITY or NaN. if (isFinite(result)) { // … }
Integers are inherently finite. The closest you can get is by setting a to int‘s maximum value: #include <limits> // … int a = std::numeric_limits<int>::max(); Which would be 2^31 – 1 (or 2 147 483 647) if int is 32 bits wide on your implementation. If you really need infinity, use a floating point number … Read more
If you use ruby 1.9.2, you can use: >> Float::INFINITY #=> Infinity >> 3 < Float::INFINITY #=> true Or you can create your own constant using the following*: I’ve checked that in Ruby 1.8.6, 1.8.7, and 1.9.2 you have Float.infinite?. PositiveInfinity = +1.0/0.0 => Infinity NegativeInfinity = -1.0/0.0 => -Infinity CompleteInfinity = NegativeInfinity..PositiveInfinity => -Infinity..Infinity … Read more
double supports Infinity double inf = Double.POSITIVE_INFINITY; System.out.println(inf + 5); System.out.println(inf – inf); // same as Double.NaN System.out.println(inf * -1); // same as Double.NEGATIVE_INFINITY prints Infinity NaN -Infinity note: Infinity – Infinity is Not A Number.