Groups | Search | Server Info | Login | Register

Groups > comp.soft-sys.math.maple > #157

Re: Mod

Show all headers | View raw

Am 23.05.2011 04:10, schrieb Thomas D. Dean:
> Maple 11
> 
> 1/3 mod 7
>   5
> (1/3) mod 7
>   5
> -2 mod 7
>   5
> 
> How do I explain 1/3 mod 7 in terms of the definition?
> 
> r = a mod n
> 
> a = n*q + r
> 
> 
> tomdean
I do not know which definition of modulus might hold when maple gives me
> `mod`(1/3, 7);
print(`output redirected...`); # input placeholder
                               5
(please ignore the garbage produced by maple's interface).
Why should be 5 the outcome of a Mod(less than one),some Integer??
maxima and Mathematica give the expected value:

Mma:In[1]:= Mod[1/3,7]
Out[1]= 1/3

maxima:
/* [wxMaxima: input   start ] */
mod(1/3,7);
/* [wxMaxima: input   end   ] */
Uhh ... copy/paste does not work with wxmaxima

well, I type the shown result:
1/3

and of course, mod(1/3, Integer>=1) should be 1/3

How to get a five from mod(1/3,7) will stay to be a riddle.

Let's see if Maple gets 6.9 mod 7 correct:

`mod`(69/10, 7)

Hmm maple 14 gives me a two... it's a mess

trying an expected value greater than one:


`mod`(71/10, 7)

penetrates me with a "5"?

generally if 0<a<1 then mod(a,n)==a for any n>=1

and it is no surprise, that using *own* capabilities is more efficient
than to rely on any CAS

Back to comp.soft-sys.math.maple | Previous | Next — Previous in thread | Next in thread | Find similar

Thread

Mod "Thomas D. Dean" <tomdean@speakeasy.org> - 2011-05-22 19:10 -0700
  Re: Mod Peter Pein <petsie@dordos.net> - 2011-05-23 07:39 +0200
  Re: Mod Axel Vogt <&noreply@axelvogt.de> - 2011-05-23 08:14 +0200
    Re: Mod "G. A. Edgar" <edgar@math.ohio-state.edu.invalid> - 2011-05-23 06:04 -0600
    Re: Mod Peter Pein <petsie@dordos.net> - 2011-05-23 14:07 +0200
      Re: Mod Axel Vogt <&noreply@axelvogt.de> - 2011-05-23 14:59 +0200
        Re: Mod Ilmari Karonen <usenet2@vyznev.invalid> - 2011-05-28 22:04 +0000
          Re: Mod Joe Riel <joer@san.rr.com> - 2011-05-31 15:26 -0700
      Re: Mod "G. A. Edgar" <edgar@math.ohio-state.edu.invalid> - 2011-05-23 10:08 -0600
  Re: Mod "Nasser M. Abbasi" <nma@12000.org> - 2011-05-23 16:04 -0700

csiph-web