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remove deprecated code in continued fractions
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Frédéric Chapoton committed Oct 3, 2018
1 parent a1bfef8 commit 07d6a3b
Showing 1 changed file with 17 additions and 149 deletions.
166 changes: 17 additions & 149 deletions src/sage/rings/continued_fraction.py
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Original file line number Diff line number Diff line change
Expand Up @@ -773,24 +773,6 @@ def numerator(self, n):

p = numerator

def pn(self, n):
r"""
Return the numerator of the `n`-th partial convergent of ``self``.
This method is deprecated since :trac:`14567` and :meth:`numerator`
should be used instead.
EXAMPLES::
sage: continued_fraction([1,2,3,5,4]).pn(3)
doctest:...: DeprecationWarning: pn is deprecated. Use the methods p or numerator instead.
See http://trac.sagemath.org/14567 for details.
53
"""
from sage.misc.superseded import deprecation
deprecation(14567, 'pn is deprecated. Use the methods p or numerator instead.')
return self.numerator(n)

def denominator(self, n):
"""
Return the denominator of the ``n``-th partial convergent of ``self``.
Expand All @@ -813,24 +795,6 @@ def denominator(self, n):

q = denominator

def qn(self, n):
r"""
Return the denominator of the ``n``-th partial convergent of ``self``.
This method is deprecated since :trac:`14567`. Use :meth:`denominator`
instead.
EXAMPLES::
sage: continued_fraction([1,2,3,12,1]).qn(3)
doctest:...: DeprecationWarning: qn is deprecated. Use the methods q or denominator instead.
See http://trac.sagemath.org/14567 for details.
93
"""
from sage.misc.superseded import deprecation
deprecation(14567, 'qn is deprecated. Use the methods q or denominator instead.')
return self.denominator(n)

def convergent(self, n):
"""
Return the ``n``-th partial convergent to self.
Expand Down Expand Up @@ -1966,7 +1930,7 @@ def __init__(self, w, value=None, check=True):
x = R(value)
y = R(self)
if x.lower() > y.lower() or x.upper() < y.upper():
raise ValueError("value evaluates to %s while the continued fraction evaluates to %s in %s."%(x,y,R))
raise ValueError("value evaluates to %s while the continued fraction evaluates to %s in %s." % (x, y, R))

self._value = value

Expand Down Expand Up @@ -2280,19 +2244,19 @@ def continued_fraction_list(x, type="std", partial_convergents=False, bits=None,

if type == "hj":
l = QQ(x).continued_fraction_list("hj")
## The C-code in sage.rings.rational is much more faster than the pure
## Python below
## v = []
## while True:
## div, mod = divmod(x.numerator(), x.denominator())
## if mod == 0:
## v.append(div)
## break
## v.append(div+1)
## if nterms is not None and len(v) >= nterms:
## break
## x = 1/(div+1-x)
## return v
# The C-code in sage.rings.rational is much more faster than the pure
# Python below
# v = []
# while True:
# div, mod = divmod(x.numerator(), x.denominator())
# if mod == 0:
# v.append(div)
# break
# v.append(div+1)
# if nterms is not None and len(v) >= nterms:
# break
# x = 1/(div+1-x)
# return v
if nterms is None:
return l
return l[:nterms]
Expand All @@ -2319,7 +2283,7 @@ def continued_fraction_list(x, type="std", partial_convergents=False, bits=None,
pass

if cf is None:
raise ValueError("does not know how to compute the continued fraction of %s"%x)
raise ValueError("does not know how to compute the continued fraction of %s" % x)

if nterms:
limit = min(cf.length(), nterms)
Expand Down Expand Up @@ -2486,7 +2450,7 @@ def continued_fraction(x, value=None):
raise ValueError("word with unknown length can not be converted to continued fractions")

# input for numbers
#TODO: the approach used below might be not what the user expects as we
# TODO: the approach used below might be not what the user expects as we
# have currently in sage (version 6.8)
#
# sage: RR.random_element() in QQ
Expand Down Expand Up @@ -2515,7 +2479,7 @@ def continued_fraction(x, value=None):
try:
RIF(x)
is_real = True
except (AttributeError,ValueError):
except (AttributeError, ValueError):
pass

if is_real is False:
Expand All @@ -2533,41 +2497,6 @@ def continued_fraction(x, value=None):
return continued_fraction(continued_fraction_list(x))


def Hirzebruch_Jung_continued_fraction_list(x, bits=None, nterms=None):
r"""
Return the Hirzebruch-Jung continued fraction of ``x`` as a list.
This function is deprecated since :trac:`14567`. See
:func:`continued_fraction_list` and the documentation therein.
INPUT:
- ``x`` -- exact rational or something that can be numerically
evaluated. The number to compute the continued fraction of.
- ``bits`` -- integer (default: the precision of ``x``). the
precision of the real interval field that is used
internally. This is only used if ``x`` is not an exact fraction.
- ``nterms`` -- integer (default: None). The upper bound on the
number of terms in the continued fraction expansion to return.
A lits of integers, the coefficients in the Hirzebruch-Jung continued
fraction expansion of ``x``.
EXAMPLES::
sage: Hirzebruch_Jung_continued_fraction_list(17/11)
doctest:...: DeprecationWarning: Hirzebruch_Jung_continued_fraction_list(x) is replaced by
continued_fraction_list(x,type="hj")
or for rationals
x.continued_fraction_list(type="hj")
See http://trac.sagemath.org/14567 for details.
[2, 3, 2, 2, 2, 2]
"""
from sage.misc.superseded import deprecation
deprecation(14567, 'Hirzebruch_Jung_continued_fraction_list(x) is replaced by\n\tcontinued_fraction_list(x,type="hj")\nor for rationals\n\tx.continued_fraction_list(type="hj")')
return continued_fraction_list(x, type="hj", bits=bits, nterms=nterms)

def convergents(x):
r"""
Return the (partial) convergents of the number ``x``.
Expand All @@ -2578,64 +2507,3 @@ def convergents(x):
[0, 1, 1/2, 4/7, 5/9, 9/16, 14/25, 23/41, 60/107, 143/255]
"""
return continued_fraction(x).convergents()


def farey(v, lim):
"""
Return the Farey sequence associated to the floating point number
v.
INPUT:
- ``v`` - float (automatically converted to a float)
- ``lim`` - maximum denominator.
OUTPUT: Results are (numerator, denominator); (1, 0) is "infinity".
EXAMPLES::
sage: farey(2.0, 100)
doctest:...: DeprecationWarning: farey is deprecated.
See http://trac.sagemath.org/14567 for details.
(2, 1)
sage: farey(2.0, 1000)
(2, 1)
sage: farey(2.1, 1000)
(21, 10)
sage: farey(2.1, 100000)
(21, 10)
sage: farey(pi, 100000)
(312689, 99532)
AUTHORS:
- Scott David Daniels: Python Cookbook, 2nd Ed., Recipe 18.13
"""
from sage.misc.superseded import deprecation
deprecation(14567, 'farey is deprecated.')

v = float(v)
if v < 0:
n, d = farey(-v, lim)
return -n, d
z = lim - lim # Get a "0 of the right type" for denominator
lower, upper = (z, z+1), (z+1, z)
while True:
mediant = (lower[0] + upper[0]), (lower[1] + upper[1])
if v * mediant[1] > mediant[0]:
if lim < mediant[1]:
return upper
lower = mediant
elif v * mediant[1] == mediant[0]:
if lim >= mediant[1]:
return mediant
if lower[1] < upper[1]:
return lower
return upper
else:
if lim < mediant[1]:
return lower
upper = mediant

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