#14088: Comparison of python and sage complex numbers
--------------------------------+-------------------------------------------
Reporter: tscrim | Owner: tscrim
Type: defect | Status: new
Priority: major | Milestone: sage-5.7
Component: basic arithmetic | Keywords:
Work issues: | Report Upstream: N/A
Reviewers: | Authors:
Merged in: | Dependencies:
Stopgaps: |
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We have the following behavior:
{{{
sage: complex('inf')
(inf+0j)
sage: CC(oo)
+infinity
sage: complex('inf') < complex(0) # This is good
---------------------------------------------------------------------------
TypeError Traceback (most recent call
last)
<ipython-input-84-743f29f99a3c> in <module>()
----> 1 complex('inf') < complex(Integer(0))
TypeError: no ordering relation is defined for complex numbers
sage: complex('inf') < float(0) # Still good
---------------------------------------------------------------------------
TypeError Traceback (most recent call
last)
<ipython-input-85-ec0c40060e5d> in <module>()
----> 1 complex('inf') < float(Integer(0))
TypeError: no ordering relation is defined for complex numbers
# These are all not good
sage: complex('inf') < 0
True
sage: complex(oo) < RR(0)
True
sage: complex(oo) < RR(oo)
False
sage: complex(oo) < RR(-oo)
True
}}}
We also have the comparison failures with sage's complex infinity:
{{{
sage: CC(oo) < 0 # This is okay
False
sage: CC(oo) > 0
True
sage: CC(oo) > CC(2+5*i)
True
sage: CC(2+4*i) < CC(2+5*i)
True
sage: CC(2+6*i) < CC(2+5*i)
False
}}}
I believe all comparisons in the complex number should raise a `TypeError`
to be consistent with python. The other alternative should be they always
return `False`.
There is also the related #11506.
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/14088>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
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