[asterisk-bugs] [JIRA] (ASTERISK-26493) Is REMAINDER behaving in intended way?

[Asterisk Team (JIRA)]

    [ https://issues.asterisk.org/jira/browse/ASTERISK-26493?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=232812#comment-232812 ] 

Asterisk Team commented on ASTERISK-26493:
------------------------------------------

Thanks for creating a report! The issue has entered the triage process. That means the issue will wait in this status until a Bug Marshal has an opportunity to review the issue. Once the issue has been reviewed you will receive comments regarding the next steps towards resolution.

A good first step is for you to review the [Asterisk Issue Guidelines|https://wiki.asterisk.org/wiki/display/AST/Asterisk+Issue+Guidelines] if you haven't already. The guidelines detail what is expected from an Asterisk issue report.

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> Is REMAINDER behaving in intended way?
> --------------------------------------
>
>                 Key: ASTERISK-26493
>                 URL: https://issues.asterisk.org/jira/browse/ASTERISK-26493
>             Project: Asterisk
>          Issue Type: Bug
>      Security Level: None
>          Components: Core/General
>    Affects Versions: 14.0.1
>         Environment: Linux 4.4.0-38-generic #57-Ubuntu SMP Tue Sep 6 15:42:33 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
>            Reporter: Jonathan Harris
>            Severity: Minor
>
> I was having issues with getting minutes and seconds from seconds, using some code provided by another user, using remainder I was getting negative seconds.
> James Thomas helped me find a workaround, but from what he wrote, I wonder if REMAINDER is behaving as expected?
>  the following test dialplan shows what I mean:
> {code}
>  exten => 7,1,Verbose(Context: ${CONTEXT} Exten:${EXTEN}) 
>     same => n,Set(seconds=57)
>     same => n,While($[${seconds} <= 400]);
>     same => n,Set(minutes=$[FLOOR(${seconds} / 60)])
>     same => n,Set(myRemainderSec=$[REMAINDER(${seconds},60)])
>     same => n,SET(myModSec=${MATH(${seconds}%60,int)})  
>     same => n,Verbose(1,Seconds:${seconds} = Minutes:${minutes} Remainder Seconds:${myRemainderSec} modulo seconds:${myModSec})
>     same => n,Set(seconds=$[${seconds}+3])
>     same => n,EndWhile()
> {code}
> This is the output:
> {code}
>  Seconds:57 = Minutes:0 Remainder Seconds:-3 modulo seconds:57
>  Seconds:60 = Minutes:1 Remainder Seconds:0 modulo seconds:0
>  Seconds:63 = Minutes:1 Remainder Seconds:3 modulo seconds:3
>  Seconds:66 = Minutes:1 Remainder Seconds:6 modulo seconds:6
>  Seconds:69 = Minutes:1 Remainder Seconds:9 modulo seconds:9
>  Seconds:72 = Minutes:1 Remainder Seconds:12 modulo seconds:12
>  Seconds:75 = Minutes:1 Remainder Seconds:15 modulo seconds:15
>  Seconds:78 = Minutes:1 Remainder Seconds:18 modulo seconds:18
>  Seconds:81 = Minutes:1 Remainder Seconds:21 modulo seconds:21
>  Seconds:84 = Minutes:1 Remainder Seconds:24 modulo seconds:24
>  Seconds:87 = Minutes:1 Remainder Seconds:27 modulo seconds:27
>  Seconds:90 = Minutes:1 Remainder Seconds:-30 modulo seconds:30
>  Seconds:93 = Minutes:1 Remainder Seconds:-27 modulo seconds:33
>  Seconds:96 = Minutes:1 Remainder Seconds:-24 modulo seconds:36
>  Seconds:99 = Minutes:1 Remainder Seconds:-21 modulo seconds:39
>  Seconds:102 = Minutes:1 Remainder Seconds:-18 modulo seconds:42
>  Seconds:105 = Minutes:1 Remainder Seconds:-15 modulo seconds:45
>  Seconds:108 = Minutes:1 Remainder Seconds:-12 modulo seconds:48
>  Seconds:111 = Minutes:1 Remainder Seconds:-9 modulo seconds:51
>  Seconds:114 = Minutes:1 Remainder Seconds:-6 modulo seconds:54
>  Seconds:117 = Minutes:1 Remainder Seconds:-3 modulo seconds:57
>  Seconds:120 = Minutes:2 Remainder Seconds:0 modulo seconds:0
> {code}
> James Thomas wrote:
> {quote}
> All I can tell you is where -3 comes from. 
> From http://www.voip-info.org/wiki/view/Asterisk+Expressions :
> REMAINDER(x,y) computes the remainder of dividing x by y. The return value is x - n*y, where n is the value x/y, rounded to the nearest integer. If this quotient is 1/2, it is rounded to the nearest even number.
> -3 comes from:
> n = x/y = 957/60 = 15.95 which rounds to 16
> n*y = 16*60 = 960
> x - 960 = 957-960 = -3
> I'm not mathematically gifted either but I think the n is the problem. it shouldn't be the rounded result it should be the integer part of x/y (n=15)
> Can you just use modulo instead: ${MATH(${myNum}%60,int)}
> {quote}
> The reason I'm filing this as a potential bug is that all other tools I've tried round it correctly, but REMAINDER acts differently. So just checking...



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