Exemple #1
0
def check_expression(expr, var_symbols, only_from_sympy=False):
    """
    Does ``eval(expr)`` both in Sage and SymPy and does other checks.

    EXAMPLES::

        sage: from sage.interfaces.sympy import check_expression
        sage: check_expression("1.123*x", "x")
    """
    from sage.symbolic.ring import SR
    from sympy import (__dict__ as sympydict, Basic, S, var as svar)
    # evaluate the expression in the context of Sage:
    if var_symbols:
        SR.var(var_symbols)
    is_different = False
    try:
        e_sage = SR(expr)
        assert not isinstance(e_sage, Basic)
    except (NameError, TypeError):
        is_different = True

    # evaluate the expression in the context of SymPy:
    if var_symbols:
        svar(var_symbols)
    b = globals().copy()
    b.update(sympydict)
    assert "sin" in b
    b.update(sympydict)
    e_sympy = eval(expr, b)
    assert isinstance(e_sympy, Basic)

    # Sympy func may have specific _sage_ method
    if is_different:
        _sage_method = getattr(e_sympy.func, "_sage_")
        e_sage = _sage_method(S(e_sympy))

    # Do the actual checks:
    if not only_from_sympy:
        assert S(e_sage) == e_sympy
    assert e_sage == SR(e_sympy)
Exemple #2
0
def check_expression(expr, var_symbols, only_from_sympy=False):
    """
    Does ``eval(expr)`` both in Sage and SymPy and does other checks.

    EXAMPLES::

        sage: from sage.interfaces.sympy import check_expression
        sage: check_expression("1.123*x", "x")
    """
    from sage import __dict__ as sagedict
    from sage.symbolic.ring import SR
    from sympy import (__dict__ as sympydict, Basic, S, var as svar)
    # evaluate the expression in the context of Sage:
    if var_symbols:
        SR.var(var_symbols)
    is_different = False
    try:
        e_sage = SR(expr)
        assert not isinstance(e_sage, Basic)
    except (NameError, TypeError):
        is_different = True
        pass

    # evaluate the expression in the context of SymPy:
    if var_symbols:
        sympy_vars = svar(var_symbols)
    b = globals().copy()
    b.update(sympydict)
    assert "sin" in b
    b.update(sympydict)
    e_sympy = eval(expr, b)
    assert isinstance(e_sympy, Basic)

    # Sympy func may have specific _sage_ method
    if is_different:
        _sage_method = getattr(e_sympy.func, "_sage_")
        e_sage = _sage_method(S(e_sympy))

    # Do the actual checks:
    if not only_from_sympy:
        assert S(e_sage) == e_sympy
    assert e_sage == SR(e_sympy)