infinity

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

来源： https://stackoverflow.com/questions/64695252/numerical-solution-for-integral-between-inf-and-inf-error-non-finite-function

问题 I need to remove logarithms of my data and thus am taking e to the power of the values which are logarithmed. My issue is that when I have e to the power of more than 709 R returns the value of infinity. How can I surpass this? e^710 [1] Inf Thanks :) 回答1: If you really want to work with numbers that big you can use a Rmpfr package. library('Rmpfr') x <- mpfr(710, precBits = 106) exp(x) 1 'mpfr' number of precision 106 bits [1] 2.233994766161711031253644458116e308 来源： https://stackoverflow

问题 What are the benefits of NaN , PositiveInfinity or NegativeInfinity for float and double ? When should we use or avoid them? If there are constants like these, why does float.Parse("a") throw an error rather than returning float.NaN ? How is NaN different than null ? Why is division by zero even possible for floating types? 回答1: Infinities are used because they are part of the arithmetic system supported by floating point. There are various operations, such as dividing by zero, in which

问题 I'm using the warnings module to raise warnings as errors. When I call my function plot_fig_4 , I get the following error: In [5]: plot_amit.plot_fig_4() g: 1 of 3 theta_E: 1 of 1000 --------------------------------------------------------------------------- RuntimeWarning Traceback (most recent call last) <ipython-input-5-5a631d2493d7> in <module>() ----> 1 plot_amit.plot_fig_4() /home/dan/Science/dopa_net/plot_amit.pyc in plot_fig_4() 130 tau_0, tau, 131 theta_E_, --> 132 H) 133 134 #

问题 I have a problem when running with Meteor. I have a "question" page which I want to increase the count view whenever it is rendered. So in my template function I write Template.questionview.helpers({ question : function() { if(Session.equals('main_template_name', 'question')) { console.log(Session.get('question_id')); Questions.update({ _id: Session.get('question_id') }, { $inc: { views: 1 } }); } }); Now here comes the problem, when I render the question view and update the question item,

问题 In the course of writing a program that accepts tsrange literals from the user, which are then plugged into various SQL queries, today I was testing some tsranges to see how they are interpreted by PostgreSQL 9.3.5. This one, in particular, behaves strangely: '(-infinity,today)'::tsrange The lower_inf function says the lower bound is not infinite (!) test=> SELECT lower_inf('(-infinity,today)'::tsrange); lower_inf ----------- f (1 row) Yet PostgreSQL reports that this tsrange contains a

问题 I'm not a mathematician, but I assume dividing by infinity is either bad math, or, at the very least, impractical. I just spend a half hour debugging my javascript that was working perfectly fine in Firefox but was giving me an error in IE. I finally realized it was because in certain scenarios, I was asking IE to divide by infinity. So, I fixed that, but I'm curious as to why Firefox was OK with that. Admittedly, this might be more of a mathematics question than programming. ;) 回答1: I think

问题 Is there a way to represent infinity (as a float/double, or NSNumber, etc.) in objective C? In other words, is there a float/double/NSNumber value that is always larger than any other value in objective C? 回答1: There's a macro for this INFINITY , float x = INFINITY; You can find this in usr/include/math.h # define HUGE_VALF __builtin_huge_valf() ... #define INFINITY HUGE_VALF Edit Some more interesting read here http://www.gnu.org/software/libc/manual/html_node/Infinity-and-NaN.html 来源： https

问题 The gnuplot command set datafile missing "nan" tells gnuplot to ignore nan data values in the data file. How to ignore both nan and -nan ? I tried the following in gnuplot, but then the effect of the first statement is overwritten by the next. gnuplot> set datafile missing "-nan" gnuplot> set datafile missing "nan" Is it possible to somewhow embed a grep -v nan in the gnuplot command, or even some kind of regexp to exclude any imaginable non-numerical data? 回答1: It is not possible to use a