latex printing with piecewise function : reversed expr and cond

[sympy-issue-migrator]

>>x=Symbol('x')
>>p = Piecewise((x,x<0),(0,x>=0))
>>latex(p)

'\\begin{cases} x & \\text{for}\\: x < 0 \\\\0 \\leq x & \\text{for}\\: 0 \\end{cases}'

second expr and cond are reversed.

with the attached patch to sympy/printing/latex.py :

'\\begin{cases} x & \\text{for}\\: x < 0 \\\\0 & \\text{for}\\: 0 \\leq x \\end{cases}'

Original issue for #5200: http://code.google.com/p/sympy/issues/detail?id=2101
Original author: https://code.google.com/u/104102615266264925881/
Original owner: https://code.google.com/u/102137482174297837682/

[asmeurer]

If I try compiling \\begin{cases} x & \\text{for}\\: x < 0 \\\\0 & \\text{for}\\: 0 \\leq x \\end{cases}, I get "Misaligned alignment tab character &".  

Also, can you add a test?

**Status:** Accepted  
**Labels:** NeedsBetterPatch Maurice.Bremond Printing  

Original comment: http://code.google.com/p/sympy/issues/detail?id=2101#c1
Original author: https://code.google.com/u/asmeurer@gmail.com/

[sympy-issue-migrator]

>If I try compiling \\begin{cases} x & \\text{for}\\: x < 0 \\\\0 &
>\\text{for}\\: 0 \\leq x \\end{cases}, I get "Misaligned alignment tab character &".

I do not have this (My laptop is ubuntu 10.4 with std latex packages).

Here is what I do : 

from sympy import *
import sympy.galgebra.latex_ex as tex

tex.Format()
print "\\begin{cases} x & \\text{for}\\: x < 0 \\\\0 & \\text{for}\\: 0 \\leq x \\end{cases}" 
tex.xdvi(filename='Piecewise.tex')

>Also, can you add a test?
Yes I will do that

Maurice

Original comment: http://code.google.com/p/sympy/issues/detail?id=2101#c2
Original author: https://code.google.com/u/104102615266264925881/

[flacjacket]

See https://github.com/sympy/sympy/pull/1009 Aaron, what was posted here should have been right, I think you need to include the amsmath package.

Original comment: http://code.google.com/p/sympy/issues/detail?id=2101#c3
Original author: https://code.google.com/u/113046012287564521760/

[asmeurer]

Right.  I may have actually forgotten to convert the \\ into \.

Original comment: http://code.google.com/p/sympy/issues/detail?id=2101#c4
Original author: https://code.google.com/u/asmeurer@gmail.com/

[asmeurer]

**Status:** Valid  

Original comment: http://code.google.com/p/sympy/issues/detail?id=2101#c5
Original author: https://code.google.com/u/asmeurer@gmail.com/

[ness01]

Fixed: https://github.com/sympy/sympy/pull/1174

**Status:** Fixed  

Original comment: http://code.google.com/p/sympy/issues/detail?id=2101#c6
Original author: https://code.google.com/u/104531927090589914088/

[jrioux]

**Owner:** julien.r...@gmail.com  
**Labels:** -NeedsBetterPatch  

Original comment: http://code.google.com/p/sympy/issues/detail?id=2101#c7
Original author: https://code.google.com/u/102137482174297837682/