Ejemplo n.º 1
0
def _single_variate(base_ring, names, sparse):
    """
    EXAMPLES::

        sage: from sage.rings.polynomial.laurent_polynomial_ring import _single_variate
        sage: _single_variate(QQ, ('x',), False)
        Univariate Laurent Polynomial Ring in x over Rational Field
    """
    ############################################################
    # This should later get moved to an actual single variate  #
    # implementation with valuation tracking,                  #
    # but I don't want to right now.                           #
    ############################################################
    # We need to come up with a name for the inverse that is easy to search
    # for in a string *and* doesn't overlap with the name that we already have.
    # For now, I'm going to use a name mangling with checking method.
    names = normalize_names(1, names)
    key = (base_ring, names, sparse)
    P = _get_from_cache(key)
    if P is not None:
        return P
    prepend_string = "qk"
    while True:
        if prepend_string in names:
            prepend_string += 'k'
        else:
            break
    R = _multi_variate_poly(base_ring, names, 1, sparse, 'degrevlex', None)
    P = LaurentPolynomialRing_mpair(R, prepend_string, names)
    _save_in_cache(key, P)
    return P
Ejemplo n.º 2
0
def _single_variate(base_ring, names, sparse):
    """
    EXAMPLES::

        sage: from sage.rings.polynomial.laurent_polynomial_ring import _single_variate
        sage: _single_variate(QQ, ('x',), False)
        Univariate Laurent Polynomial Ring in x over Rational Field
    """
    ############################################################
    # This should later get moved to an actual single variate  #
    # implementation with valuation tracking,                  #
    # but I don't want to right now.                           #
    ############################################################
    # We need to come up with a name for the inverse that is easy to search
    # for in a string *and* doesn't overlap with the name that we already have.
    # For now, I'm going to use a name mangling with checking method.
    names = normalize_names(1, names)
    key = (base_ring, names, sparse)
    P = _get_from_cache(key)
    if P is not None:
        return P
    prepend_string = "qk"
    while True:
        if prepend_string in names:
            prepend_string += 'k'
        else:
            break
    R = _multi_variate_poly(base_ring, names, 1, sparse, 'degrevlex', None)
    P = LaurentPolynomialRing_mpair(R, prepend_string, names)
    _save_in_cache(key, P)
    return P
Ejemplo n.º 3
0
def _multi_variate(base_ring, names, n, sparse, order):
    """
    EXAMPLES::

        sage: from sage.rings.polynomial.laurent_polynomial_ring import _multi_variate
        sage: _multi_variate(QQ, ('x','y'), 2, False, 'degrevlex')
        Multivariate Laurent Polynomial Ring in x, y over Rational Field
    """
    # We need to come up with a name for the inverse that is easy to search
    # for in a string *and* doesn't overlap with the name that we already have.
    # For now, I'm going to use a name mangling with checking method.
    names = normalize_names(n, names)

    from .term_order import TermOrder
    order = TermOrder(order, n)

    if isinstance(names, list):
        names = tuple(names)
    elif isinstance(names, str):
        if ',' in names:
            names = tuple(names.split(','))

    key = (base_ring, names, n, sparse, order)
    P = _get_from_cache(key)
    if P is not None:
        return P
    prepend_string = "qk"
    while True:
        for a in names:
            if prepend_string in a:
                prepend_string += 'k'
                break
        else:
            break
    R = _multi_variate_poly(base_ring, names, n, sparse, order, None)
    P = LaurentPolynomialRing_mpair(R, prepend_string, names)
    _save_in_cache(key, P)
    return P
def _multi_variate(base_ring, names, n, sparse, order):
    """
    EXAMPLES::

        sage: from sage.rings.polynomial.laurent_polynomial_ring import _multi_variate
        sage: _multi_variate(QQ, ('x','y'), 2, False, 'degrevlex')
        Multivariate Laurent Polynomial Ring in x, y over Rational Field
    """
    # We need to come up with a name for the inverse that is easy to search
    # for in a string *and* doesn't overlap with the name that we already have.
    # For now, I'm going to use a name mangling with checking method.
    names = normalize_names(n, names)

    from term_order import TermOrder
    order = TermOrder(order, n)

    if isinstance(names, list):
        names = tuple(names)
    elif isinstance(names, str):
        if ',' in names:
            names = tuple(names.split(','))

    key = (base_ring, names, n, sparse, order)
    P = _get_from_cache(key)
    if P is not None:
        return P
    prepend_string = "qk"
    while True:
        for a in names:
            if prepend_string in a:
                prepend_string += 'k'
                break
        else:
            break
    R = _multi_variate_poly(base_ring, names, n, sparse, order, None)
    P = LaurentPolynomialRing_mpair(R, prepend_string, names)
    _save_in_cache(key, P)
    return P