For what it's worth, Matlab produces 72057594037927936. In general, 64-bit math is limited in accuracy to between 16 and 17 decimal digits, depending how well that number "fits" into a floating point representation.
----- Original Message ----- From: "Gordon Smith" <[email protected]> To: "users, apache" <[email protected]> Sent: Tuesday, November 11, 2014 2:37:08 PM Subject: RE: Math.pow in ActionScript NO NO NO. 16 to the power 14 is indeed 72057594037927936. Calculator is absolutely correct. It is presumably doing high-precision integer arithmetic. ActionScript is using floating point arithmetic, since you can ask for things like Math.pow(16.1, 14.2). It doesn't special case on integers, and even if it did it doesn't do high-precision integer arithmetic. It gets the wrong answer because floating-point numbers don't have a sufficient number of significant digits to produce a 17-digit result exactly. It simply computes powers by taking the log() of the first argument, multiplying it by the second argument, and then taking the exp() of the result, because a^b = e^(ln(a^b)) = e^(b ln(a)). These are all floating-point operations. - Gordon > From: [email protected] > Date: Tue, 11 Nov 2014 19:48:38 +0100 > Subject: Re: Math.pow in ActionScript > To: [email protected] > > Don't worry at all about the Calculator result :) > > http://www.askvg.com/microsoft-windows-calculator-bug/ > > The math engine of the calculator is well known as quite buggy :) Once > again, ActionScript is right :) > > On Tue, Nov 11, 2014 at 7:39 PM, OmPrakash Muppirala <[email protected]> > wrote: > > > Doing a Math.pow(16,14) in JavaScript results in 72057594037927940 as well. > > Google's calculator gives the same answer as well: > > http://lmgtfy.com/?q=16+to+the+power+of+14 > > > > Majority wins, I guess ;-) > > > > On Tue, Nov 11, 2014 at 10:25 AM, Harbs <[email protected]> wrote: > > > > > I’m not sure why you think it’s not using floats. > > > > > > Take a look here: > > > > > > > > http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/Math.html > > > > > > > > Specifically: > > > Note: The Math functions acos, asin, atan, atan2, cos, exp, log, pow, > > sin, > > > and sqrt may result in slightly different values depending on the > > > algorithms used by the CPU or operating system. Flash runtimes call on > > the > > > CPU (or operating system if the CPU doesn't support floating point > > > calculations) when performing the calculations for the listed functions, > > > and results have shown slight variations depending upon the CPU or > > > operating system in use. > > > > > > Harbs > > > > > > On Nov 11, 2014, at 7:50 PM, Devesh Mishra(NABFS00) < > > > [email protected]> wrote: > > > > > > > It's not floating point number. So I don't think so. > > > > > > > > -- > > > > Thanks & Regards, > > > > Devesh Mishra > > > > > > > > -----Original Message----- > > > > From: Subscriptions [mailto:[email protected]] > > > > Sent: Tuesday, November 11, 2014 10:44 PM > > > > To: [email protected] > > > > Subject: Re: Math.pow in ActionScript > > > > > > > > presumably due to precision issues with large numbers (ie not your > > > > fault) eg: > > http://en.wikipedia.org/wiki/Floating_point#Accuracy_problems > > > > > > > > Lee Burrows > > > > ActionScripter > > > > > > > > On 11/11/2014 16:38, Devesh Mishra(NABFS00) wrote: > > > >> Hi, > > > >> > > > >> I am using Math.pow(x,y) method in action script. But I am very > > > surprised with the results. > > > >> > > > >> For example, Math.pow(16,14). > > > >> > > > >> In Action Script, it gives: 72057594037927940 > > > >> In Calculator, it gives: 72057594037927936 > > > >> > > > >> What may be the reason for this difference , Any idea ! > > > >> > > > >> > > > >> -- > > > >> Thanks & Regards, > > > >> Devesh Mishra > > > >> > > > >> > > > >> > > > > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Disclaimer~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > > > > >> Information contained and transmitted by this e-mail is confidential > > > and proprietary to IGATE and its affiliates and is intended for use only > > by > > > the recipient. 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