On Fri, 2009-07-24 at 21:10 +0200, Vinzent Steinberg wrote:
> 2009/7/21 Fabian Pedregosa <fab...@fseoane.net>:
> >
> > This is now independent from objects and out of the core. Assume is
> > the basic object is this new model, and it is only a container
> > (all logic is done by sympy.logic and sympy.queries).
> > ---
> > sympy/__init__.py | 2 +-
> > sympy/assumptions/__init__.py | 2 +
> > sympy/assumptions/assume.py | 97
> > +++++++++++++++++++++++++
> > sympy/assumptions/tests/test_assumptions_2.py | 58 +++++++++++++++
> > sympy/printing/pretty/pretty.py | 3 +
> > 5 files changed, 161 insertions(+), 1 deletions(-)
> > create mode 100644 sympy/assumptions/__init__.py
> > create mode 100644 sympy/assumptions/assume.py
> > create mode 100644 sympy/assumptions/tests/test_assumptions_2.py
> >
> > diff --git a/sympy/__init__.py b/sympy/__init__.py
> > index 3be16a4..c813490 100644
> > --- a/sympy/__init__.py
> > +++ b/sympy/__init__.py
> > @@ -21,7 +21,7 @@ def __sympy_debug():
> >
> > import symbol as stdlib_symbol
> > from sympy.core import *
> > -
> > +from assumptions import *
> > from polys import *
> > from series import *
> > from functions import *
> > diff --git a/sympy/assumptions/__init__.py b/sympy/assumptions/__init__.py
> > new file mode 100644
> > index 0000000..bdd47c2
> > --- /dev/null
> > +++ b/sympy/assumptions/__init__.py
> > @@ -0,0 +1,2 @@
> > +from assume import Assume, register_global_assumptions,
> > list_global_assumptions, \
> > + remove_global_assumptions, clean_global_assumptions
> > diff --git a/sympy/assumptions/assume.py b/sympy/assumptions/assume.py
> > new file mode 100644
> > index 0000000..4069ee9
> > --- /dev/null
> > +++ b/sympy/assumptions/assume.py
> > @@ -0,0 +1,97 @@
> > +# doctests are disabled because of issue #1521
> > +from sympy.core import Basic, Symbol
> > +from sympy.core.relational import Relational
> > +
> > +__global_assumptions = []
> > +
> > +def register_global_assumptions(*assump):
> > + """Register an assumption as global
> > +
> > + Examples:
> > +# >>> from sympy import *
> > +# >>> list_global()
> > +# []
> > +# >>> x = Symbol('x')
> > +# >>> register_global(Assume(x, real=True))
> > +# True
> > +# >>> list_global()
> > +# [Assume(x, real=True)]
> > +
> > + You can undo this calling remove_global
> > + """
> > + __global_assumptions.extend(assump)
> > +
> > +def list_global_assumptions():
> > + """List all global assumptions"""
> > + return __global_assumptions[:] # make a copy
> > +
> > +def remove_global_assumptions(*assump):
> > + """Remove a global assumption. If argument is not
> > + a global assumption, it will raise ValueError
> > + """
> > + for assumption in assump:
> > + __global_assumptions.remove(assumption)
> > +
> > +def clean_global_assumptions():
> > + """Remove all global assumptions"""
> > + global __global_assumptions
> > + __global_assumptions = []
>
> What about a global_assumptions object with methods? I would prefer
> this over this functional approach
Yes, I also considered this approach, but for that I would need an
object GlobalAssumptions with methods .Add(), .Remove(), .Clean(). Plus,
this object should be a singleton of provide some way of preserving
data. I just felt that it was too complicated, while current approach is
much simpler (but I am willing to change it if there is a good reason to
do so).
>
> > +class Assume(Basic):
> > + """New-style assumptions
> > +
> > +# >>> from sympy import Symbol, Assume
> > +# >>> x = Symbol('x')
> > +# >>> Assume(x, integer=True)
> > +# Assume( x, integer = True )
> > +# >>> Assume(x, integer=False)
> > +# Assume( x, integer = False )
> > +# >>> Assume( x > 1 )
> > +# Assume( x > 1, relational = True)
>
> Why the additional spaces? ('( ', ' = ')
>
That's a bug, I'll correct it.
> > + """hat
> > +
> > + def __init__(self, expr, *args, **kwargs):
> > + if isinstance(expr, Symbol):
> > + key, value = kwargs.popitem()
> > + elif isinstance(expr, Relational):
> > + key, value = 'relational', True
> > + if kwargs:
> > + raise ValueError('Wrong set of arguments')
> > + self._args = (expr, key, value)
> > +
> > + is_Atom = True # do not attempt to decompose this
> > +
> > + @property
> > + def expr(self):
> > + return self._args[0]
> > +
> > + @property
> > + def key(self):
> > + return self._args[1]
> > +
> > + @property
> > + def value(self):
> > + return self._args[2]
> > +
> > + def __eq__(self, other):
> > + if type(other) == Assume:
> > + return self._args == other._args
> > + return False
> > +
> > +def eliminate_assume(expr, symbol=None):
> > + """
> > + Will convert an expression with assumptions to an equivalent with all
> > assumptions
> > + replaced by symbols
> > + Assume(x, integer=True) --> integer
> > + Assume(x, integer=False) --> ~integer
> > + """
>
> A doctest would be helpful, even if disabled.
>
indeed
> > + if type(expr) == Assume:
> > + if symbol is not None:
> > + if not expr.expr.has(symbol): return
> > + if expr.value: return Symbol(expr.key)
> > + return ~Symbol(expr.key)
> > + args = []
> > + for a in expr.args:
> > + args.append(eliminate_assume(a))
> > + return type(expr)(*args)
> > +
> > diff --git a/sympy/assumptions/tests/test_assumptions_2.py
> > b/sympy/assumptions/tests/test_assumptions_2.py
> > new file mode 100644
> > index 0000000..d95162f
> > --- /dev/null
> > +++ b/sympy/assumptions/tests/test_assumptions_2.py
> > @@ -0,0 +1,58 @@
> > +"""rename this to test_assumptions.py when the old assumptions system is
> > deleted"""
> > +from sympy.core import symbols
> > +from sympy.assumptions import Assume, register_global_assumptions, \
> > + list_global_assumptions, remove_global_assumptions,
> > clean_global_assumptions
> > +from sympy.assumptions.assume import eliminate_assume
> > +from sympy.printing import pretty
> > +
> > +def test_assume():
> > + x = symbols('x')
> > + assump = Assume(x, integer=True)
> > + assert assump.expr == x
> > + assert assump.key == 'integer'
> > + assert assump.value == True
> > +
> > +def test_False():
> > + """Test Assume object with False keys"""
> > + x = symbols('x')
> > + assump = Assume(x, integer=False)
> > + assert assump.expr == x
> > + assert assump.key == 'integer'
> > + assert assump.value == False
> > +
> > +def test_equal():
> > + """Test for equality"""
> > + x = symbols('x')
> > + assert Assume(x, positive=True) == Assume(x, positive=True)
> > + assert Assume(x, positive=True) != Assume(x, positive=False)
> > + assert Assume(x, positive=False) == Assume(x, positive=False)
> > +
> > +def test_pretty():
> > + x = symbols('x')
> > + assert pretty(Assume(x, positive=True)) == 'Assume(x, positive=True)'
> > +
> > +def test_eliminate_assumptions():
> > + a, b, x, y = symbols('abxy')
> > + assert eliminate_assume(Assume(x, a=True)) == a
> > + assert eliminate_assume(Assume(x, a=True), symbol=x) == a
> > + assert eliminate_assume(Assume(x, a=True), symbol=y) == None
> > + assert eliminate_assume(Assume(x, a=False)) == ~a
> > + assert eliminate_assume(Assume(x, a=False), symbol=y) == None
> > + assert eliminate_assume(Assume(x, a=True) | Assume(x, b=True)) == a | b
> > + assert eliminate_assume(Assume(x, a=True) | Assume(x, b=False)) == a |
> > ~b
> > +
> > +def test_global():
> > + """Test for global assumptions"""
> > + x, y = symbols('x y')
> > + register_global_assumptions(Assume(x>0))
> > + assert Assume(x>0) in list_global_assumptions()
> > + remove_global_assumptions(Assume(x>0))
> > + assert (Assume(x>0) in list_global_assumptions()) == False
> > +
> > + # same with multiple of assumptions
> > + register_global_assumptions(Assume(x>0), Assume(y>0))
> > + assert Assume(x>0) in list_global_assumptions()
> > + assert Assume(y>0) in list_global_assumptions()
> > + clean_global_assumptions()
> > + assert (Assume(x>0) in list_global_assumptions()) == False
> > + assert (Assume(y>0) in list_global_assumptions()) == False
> > diff --git a/sympy/printing/pretty/pretty.py
> > b/sympy/printing/pretty/pretty.py
> > index 19ffff2..6d7f4da 100644
> > --- a/sympy/printing/pretty/pretty.py
> > +++ b/sympy/printing/pretty/pretty.py
> > @@ -56,6 +56,9 @@ def _print_Atom(self, e):
> > except KeyError:
> > return self.emptyPrinter(e)
> >
> > + def _print_Assume(self, e):
> > + return prettyForm("Assume(%s, %s=%s)" % (e.expr, e.key, e.value))
> > +
> > # Infinity inherits from Rational, so we have to override _print_XXX
> > order
> > _print_Infinity = _print_Atom
> > _print_NegativeInfinity = _print_Atom
> > --
> > 1.6.2.2
> >
> >
> > >
> >
>
> Your work on assumptions is really shaping nicely!
>
Thanks!.
> Vinzent
>
> >
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