real numbers don't support __mod__

[burcin]

sage: 10.0 % 2r
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)

/home/burcin/.sage/temp/karr/24765/_home_burcin__sage_init_sage_0.py in <module>()
----> 1 
      2 
      3 
      4 
      5 

TypeError: unsupported operand type(s) for %: 'sage.rings.real_mpfr.RealLiteral' and 'int'

A quick look through sage/rings/real_mpfr.pyx reveals that there is no __mod__ method defined.

MPFR documentation here:

http://www.mpfr.org/mpfr-current/mpfr.html#Integer-Related-Functions

suggests that one of mpfr_fmod() or mpfr_remainder() should be used, depending on the desired rounding properties. Since I live blissfully in the exact arithmetic world, I have no idea which one is more suitable for Sage.

Nevertheless, a patch that uses mpfr_remainder() is attached.

Component: basic arithmetic

Issue created by migration from https://trac.sagemath.org/ticket/5132

[zimmermann6]

comment:1

Attachment: trac_5132-mpfr_mod.patch.gz

This is a duplicate of #825.

[mwhansen]

comment:2

Looks good to me. This also fixes the broken example reported at #825.

[sagetrac-mabshoff]

comment:3

Merged in Sage 3.3.alpha4.

Cheers,

Michael