infinity

问题 I'm trying to compute a series using C++. The series is: (for those wondering) My code is the following: #include <iostream> #include <fstream> #include <cmath> // exp #include <iomanip> //setprecision, setw #include <limits> //numeric_limits (http://en.cppreference.com/w/cpp/types/numeric_limits) long double SminOneCenter(long double gamma) { using std::endl; using std::cout; long double result=0.0l; for (long double k = 1; k < 1000 ; k++) { if(isinf(pow(1.0l+pow(gamma,k),6.0l/4.0l))) { cout

问题 I'm trying to compute a series using C++. The series is: (for those wondering) My code is the following: #include <iostream> #include <fstream> #include <cmath> // exp #include <iomanip> //setprecision, setw #include <limits> //numeric_limits (http://en.cppreference.com/w/cpp/types/numeric_limits) long double SminOneCenter(long double gamma) { using std::endl; using std::cout; long double result=0.0l; for (long double k = 1; k < 1000 ; k++) { if(isinf(pow(1.0l+pow(gamma,k),6.0l/4.0l))) { cout

问题 This is a simple example of infinity scroll. How add infinity to Up scroll and insert rows at beginning: rows.insert(contentsOf: Array(repeating: "Item 0", count: 20), at: 0) Like apple do this trick in calendar. struct Screen: View { @State var rows: [String] = Array(repeating: "Item", count: 20) private func getNextPageIfNecessary(encounteredIndex: Int) { guard encounteredIndex == rows.count - 1 else { return } rows.append(contentsOf: Array(repeating: "Item", count: 20)) } var body: some

问题 math.isinf() tests for positive or negative infinity lumped together. What's the pythonic way to test for them distinctly? Ways to test for positive infinity: x == float('+inf') math.isinf(x) and x > 0 Ways to test for negative infinity: x == float('-inf') math.isinf(x) and x < 0 Disassembly Way 1: >>> def ispinf1(x): return x == float("inf") ... >>> dis.dis(ispinf1) 1 0 LOAD_FAST 0 (x) 3 LOAD_GLOBAL 0 (float) 6 LOAD_CONST 1 ('inf') 9 CALL_FUNCTION 1 12 COMPARE_OP 2 (==) 15 RETURN_VALUE

问题 math.isinf() tests for positive or negative infinity lumped together. What's the pythonic way to test for them distinctly? Ways to test for positive infinity: x == float('+inf') math.isinf(x) and x > 0 Ways to test for negative infinity: x == float('-inf') math.isinf(x) and x < 0 Disassembly Way 1: >>> def ispinf1(x): return x == float("inf") ... >>> dis.dis(ispinf1) 1 0 LOAD_FAST 0 (x) 3 LOAD_GLOBAL 0 (float) 6 LOAD_CONST 1 ('inf') 9 CALL_FUNCTION 1 12 COMPARE_OP 2 (==) 15 RETURN_VALUE

问题 math.isinf() tests for positive or negative infinity lumped together. What's the pythonic way to test for them distinctly? Ways to test for positive infinity: x == float('+inf') math.isinf(x) and x > 0 Ways to test for negative infinity: x == float('-inf') math.isinf(x) and x < 0 Disassembly Way 1: >>> def ispinf1(x): return x == float("inf") ... >>> dis.dis(ispinf1) 1 0 LOAD_FAST 0 (x) 3 LOAD_GLOBAL 0 (float) 6 LOAD_CONST 1 ('inf') 9 CALL_FUNCTION 1 12 COMPARE_OP 2 (==) 15 RETURN_VALUE

问题 math.isinf() tests for positive or negative infinity lumped together. What's the pythonic way to test for them distinctly? Ways to test for positive infinity: x == float('+inf') math.isinf(x) and x > 0 Ways to test for negative infinity: x == float('-inf') math.isinf(x) and x < 0 Disassembly Way 1: >>> def ispinf1(x): return x == float("inf") ... >>> dis.dis(ispinf1) 1 0 LOAD_FAST 0 (x) 3 LOAD_GLOBAL 0 (float) 6 LOAD_CONST 1 ('inf') 9 CALL_FUNCTION 1 12 COMPARE_OP 2 (==) 15 RETURN_VALUE

问题 So in Ruby there is a trick to specify infinity: 1.0/0 => Infinity I believe in Python you can do something like this float('inf') These are just examples though, I'm sure most languages have infinity in some capacity. When would you actually use this construct in the real world? Why would using it in a range be better than just using a boolean expression? For instance (0..1.0/0).include?(number) == (number >= 0) # True for all values of number => true To summarize, what I'm looking for is a

问题 I have a number input that I want to hold integers. If the value gets set to negative then I want the symbol shown to be ∞ ( ∞ ). Doing this doesn't work (a blank is shown instead of "∞"): <% if foo <= -1 v = '∞' else v = foo end %> <input type="number" value="<%= v %>"> Is there a way to do it without resorting to javascript? 回答1: What are your requirements for having a "number" field? Can you rely on form validation and use Javascript to progressively enhance just typing numbers. Then use

问题 What is the best way to represent infinity in a JSON API? e.g. free to read articles for this month (this will be a finite number on some subscriptions and infinite on the premium subscription). Is it a better idea to return null for this use case or to extend JSON and use the javascript's Infinity value? The latter seems more appropriate, but I've never seen an example of an API which does this. It would also be cool if anyone had any examples of public Web APIs which represent infinity. 回答1