print symbolic fractions more naturally: print 2/(x+2) instead of 2 (1/(x+2))

[jasongrout]

See http://groups.google.com/group/sage-devel/browse_frm/thread/9d58693356e11947

CC: @burcin

Component: symbolics

Keywords: pynac, symbolic, print

Author: Burcin Erocal

Reviewer: Karl-Dieter Crisman, Ross Kyprianou

Merged: sage-4.3.3.alpha1

Issue created by migration from https://trac.sagemath.org/ticket/7363

[burcin]

add doctests

[burcin]

comment:2

Attachment: trac_7363-mul_coeff.patch.gz

Next pynac release will have a patch for this. attachment: trac_7363-mul_coeff.patch fixes some doctests and adds a couple more.

[burcin]

Changed keywords from none to pynac

[burcin]

Author: Burcin Erocal

[burcin]

comment:3

New pynac package available here:

http://sage.math.washington.edu/home/burcin/pynac/pynac-0.1.11.spkg

The package contains fixes for #7822, #6961, #7876, #7363, #6465 and #6559. Apart from this ticket, #7876 contains printing changes. Doctests should be run with the patch from that ticket applied as well.

[kcrisman]

comment:4

This seems to work well, but I do not know enough C++ to review http://pynac.sagemath.org/hg/rev/5ea74f619c01, unfortunately. Partial positive review?

[sagetrac-rossk]

Reviewer: Karl-Dieter Crisman, Ross Kyprianou

[sagetrac-rossk]

Changed keywords from pynac to pynac, symbolic, print

[sagetrac-rossk]

comment:5

Im also not qualified to review the C++ code but the (representative) examples below indicate the code satisfies the objectives so Im giving it a positive review (which someone can reverse if they discover a counterexample)

# Note: division is left associative: 12/3/4 = (12/3)/4
sage: 12/3/4 
1

sage: var('x y z')
(x, y, z)

sage: 2/(x+1) # the motivating example
2/(x + 1)

sage: 1/(2*y)
1/2/y

sage: 1/(1/2*y)
2/y

sage: x/2/y
1/2*x/y

sage: .5*x/y
0.500000000000000*x/y

sage: .5/x/y
0.500000000000000/(x*y)

sage: 1/2/x/y
1/2/(x*y)

sage: 1/x/2
1/2/x

[sagetrac-mvngu]

Merged: sage-4.3.3.alpha1