#\input texinfo
"""
Unified place for determining if external dependencies are installed or not.
You should import all external modules using the import_module() function.
For example
>>> from sympy.external import import_module
>>> numpy = import_module('numpy')
If the resulting library is not installed, or if the installed version
is less than a given minimum version, the function will return None.
Otherwise, it will return the library. See the docstring of
import_module() for more information.
"""
from sympy.external.importtools import import_module
from sympy.external.importtools import import_module
disabled = False
# if pyglet.gl fails to import, e.g. opengl is missing, we disable the tests
pyglet_gl = import_module("pyglet.gl", catch=(OSError, ))
pyglet_window = import_module("pyglet.window", catch=(OSError, ))
if not pyglet_gl or not pyglet_window:
disabled = True
from sympy import symbols, sin, cos, log
x, y, z = symbols('x, y, z')
def test_import():
from sympy.plotting.pygletplot import PygletPlot
def test_plot_2d():
from sympy.plotting.pygletplot import PygletPlot
p = PygletPlot(x, [x, -5, 5, 4], visible=False)
p.wait_for_calculations()
def test_plot_2d_discontinuous():
from sympy.plotting.pygletplot import PygletPlot
p = PygletPlot(1 / x, [x, -1, 1, 2], visible=False)
p.wait_for_calculations()
def test_plot_3d():
from sympy.external.importtools import import_module
disabled = False
# if pyglet.gl fails to import, e.g. opengl is missing, we disable the tests
pyglet_gl = import_module("pyglet.gl", catch=(OSError,))
pyglet_window = import_module("pyglet.window", catch=(OSError,))
if not pyglet_gl or not pyglet_window:
disabled = True
from sympy import symbols, sin, cos
x, y, z = symbols('x, y, z')
def test_import():
from sympy.plotting.pygletplot import PygletPlot
def test_plot_2d():
from sympy.plotting.pygletplot import PygletPlot
p = PygletPlot(x, [x, -5, 5, 4], visible=False)
p.wait_for_calculations()
def test_plot_2d_discontinuous():
from sympy.plotting.pygletplot import PygletPlot
p = PygletPlot(1/x, [x, -1, 1, 2], visible=False)
p.wait_for_calculations()
def satisfiable(expr, algorithm=None, all_models=False):
"""
Check satisfiability of a propositional sentence.
Returns a model when it succeeds.
Returns {true: true} for trivially true expressions.
On setting all_models to True, if given expr is satisfiable then
returns a generator of models. However, if expr is unsatisfiable
then returns a generator containing the single element False.
Examples
========
>>> from sympy.abc import A, B
>>> from sympy.logic.inference import satisfiable
>>> satisfiable(A & ~B)
{A: True, B: False}
>>> satisfiable(A & ~A)
False
>>> satisfiable(True)
{True: True}
>>> next(satisfiable(A & ~A, all_models=True))
False
>>> models = satisfiable((A >> B) & B, all_models=True)
>>> next(models)
{A: False, B: True}
>>> next(models)
{A: True, B: True}
>>> def use_models(models):
... for model in models:
... if model:
... # Do something with the model.
... print(model)
... else:
... # Given expr is unsatisfiable.
... print("UNSAT")
>>> use_models(satisfiable(A >> ~A, all_models=True))
{A: False}
>>> use_models(satisfiable(A ^ A, all_models=True))
UNSAT
"""
if algorithm is None or algorithm == "pycosat":
pycosat = import_module('pycosat')
if pycosat is not None:
algorithm = "pycosat"
else:
if algorithm == "pycosat":
raise ImportError("pycosat module is not present")
# Silently fall back to dpll2 if pycosat
# is not installed
algorithm = "dpll2"
if algorithm == "dpll":
from sympy.logic.algorithms.dpll import dpll_satisfiable
return dpll_satisfiable(expr)
elif algorithm == "dpll2":
from sympy.logic.algorithms.dpll2 import dpll_satisfiable
return dpll_satisfiable(expr, all_models)
elif algorithm == "pycosat":
from sympy.logic.algorithms.pycosat_wrapper import pycosat_satisfiable
return pycosat_satisfiable(expr, all_models)
raise NotImplementedError
"""
Unified place for determining if external dependencies are installed or not.
You should import all external modules using the import_module() function.
For example
>>> from sympy.external import import_module
>>> numpy = import_module('numpy')
If the resulting library is not installed, or if the installed version
is less than a given minimum version, the function will return None.
Otherwise, it will return the library. See the docstring of
import_module() for more information.
"""
from sympy.external.importtools import import_module
