"""
libSingular: Options
Singular uses a set of global options to determine verbosity and the
behavior of certain algorithms. We provide an interface to these
options in the most 'natural' python-ic way. Users who do not wish to
deal with Singular functions directly usually do not have to worry
about this interface or Singular options in general since this is
taken care of by higher level functions.
We compute a Groebner basis for Cyclic-5 in two different contexts::
sage: P.<a,b,c,d,e> = PolynomialRing(GF(127))
sage: I = sage.rings.ideal.Cyclic(P)
sage: std = sage.libs.singular.ff.std
By default, tail reductions are performed::
sage: from sage.libs.singular.option import opt, opt_ctx
sage: opt['red_tail']
True
sage: std(I)[-1]
d^2*e^6 + 28*b*c*d + ...
If we don't want this, we can create an option context, which disables
this::
sage: with opt_ctx(red_tail=False, red_sb=False):
... std(I)[-1]
d^2*e^6 + 8*c^3 + ...
However, this does not affect the global state::
sage: opt['red_tail']
True
On the other hand, any assignment to an option object will immediately
change the global state::
sage: opt['red_tail'] = False
sage: opt['red_tail']
False
sage: opt['red_tail'] = True
sage: opt['red_tail']
True
Assigning values within an option context, only affects this context::
sage: with opt_ctx:
... opt['red_tail'] = False
sage: opt['red_tail']
True
Option contexts can also be safely stacked::
sage: with opt_ctx:
... opt['red_tail'] = False
... print opt
... with opt_ctx:
... opt['red_through'] = False
... print opt
...
general options for libSingular (current value 0x00000082)
general options for libSingular (current value 0x00000002)
sage: print opt
general options for libSingular (current value 0x02000082)
Furthermore, the integer valued options ``deg_bound`` and
``mult_bound`` can be used::
sage: R.<x,y> = QQ[]
sage: I = R*[x^3+y^2,x^2*y+1]
sage: opt['deg_bound'] = 2
sage: std(I)
[x^2*y + 1, x^3 + y^2]
sage: opt['deg_bound'] = 0
sage: std(I)
[y^3 - x, x^2*y + 1, x^3 + y^2]
The same interface is available for verbosity options::
sage: from sage.libs.singular.option import opt_verb
sage: opt_verb['not_warn_sb']
False
sage: opt.reset_default() # needed to avoid side effects
sage: opt_verb.reset_default() # needed to avoid side effects
AUTHOR:
- Martin Albrecht (2009-08): initial implementation
- Martin Albrecht (2010-01): better interface, verbosity options
- Simon King (2010-07): Python-ic option names; deg_bound and mult_bound
"""
from sage.libs.singular.decl cimport singular_options, singular_verbose_options, Kstd1_deg, Kstd1_mu
from sage.libs.singular.decl cimport OPT_PROT, OPT_REDSB, OPT_NOT_BUCKETS, OPT_NOT_SUGAR, OPT_SUGARCRIT, OPT_REDTHROUGH, OPT_DEGBOUND, OPT_MULTBOUND
from sage.libs.singular.decl cimport OPT_RETURN_SB, OPT_FASTHC, OPT_OLDSTD, OPT_REDTAIL, OPT_INTSTRATEGY, OPT_NOTREGULARITY
from sage.libs.singular.decl cimport OPT_WEIGHTM, Sy_bit
from sage.libs.singular.decl cimport V_SHOW_MEM, V_YACC, V_REDEFINE, V_READING, V_LOAD_LIB, V_DEBUG_LIB
from sage.libs.singular.decl cimport V_LOAD_PROC, V_DEF_RES, V_SHOW_USE, V_IMAP, V_PROMPT
from sage.libs.singular.decl cimport V_NSB, V_CONTENTSB, V_CANCELUNIT, V_DEG_STOP
_options_py_to_singular={'return_sb':'returnSB',
'fast_hc':'fastHC',
'inf_red_tail':'infRedTail',
'int_strategy':'intStrategy',
'not_regularity':'notRegularity',
'not_sugar':'notSugar',
'not_buckets':'notBuckets',
'qring_nf':'qringNF',
'redsb':'redSB',
'red_sb':'redSB',
'red_tail':'redTail',
'red_through':'redThrough',
'sugar_crit':'sugarCrit',
'weight_m':'weightM',
'content_sb':'contentSB',
'mult_bound':'multBound',
'deg_bound':'degBound',
'imap':'Imap',
'debug_lib':'debugLib',
'def_res':'defRes',
'load_lib':'loadLib',
'load_proc':'loadProc',
'not_warn_sb':'notWarnSB'}
cdef class LibSingularOptions_abstract:
"""
Abstract Base Class for libSingular options.
"""
cdef unsigned int *global_options
cdef object name
cdef object name_map
def __init__(self, **kwds):
"""
INPUT:
- ``**kwds`` - all keyword parameters are immediately applied.
EXAMPLE::
sage: from sage.libs.singular.option import LibSingularOptions
sage: opt = LibSingularOptions(redTail=False)
sage: opt['redTail']
False
sage: opt['redTail'] = True
sage: opt['redTail']
True
sage: opt['deg_bound'] = 2
The options can be named in Python or Singular style::
sage: opt['degBound']
2
"""
for k,v in kwds.iteritems():
self[k] = v
def __getitem__(self, name):
"""
EXAMPLE::
sage: from sage.libs.singular.option import opt
sage: opt['red_tail']
True
sage: opt['deg_bound'] = 2
The options can be named in Python or Singular style::
sage: opt['degBound']
2
sage: opt.reset_default() # needed to avoid side effects
"""
name = _options_py_to_singular.get(name,name)
if name == "degBound":
if bool(self.global_options[0] & self.name_map[name]):
return Kstd1_deg
return int(0)
if name == "multBound":
if bool(self.global_options[0] & self.name_map[name]):
return Kstd1_mu
return int(0)
try:
return bool(self.global_options[0] & self.name_map[name])
except KeyError:
raise NameError("Option '%s' unknown."%(name,))
def __setitem__(self, name, value):
"""
EXAMPLE::
sage: from sage.libs.singular.option import opt, opt_ctx
sage: opt['redTail']
True
sage: with opt_ctx:
... opt['redTail'] = False
... opt['redTail']
False
sage: opt['red_tail']
True
sage: opt.reset_default() # needed to avoid side effects
"""
name = _options_py_to_singular.get(name,name)
try:
if value:
self.global_options[0] = self.global_options[0] | self.name_map[name]
else:
self.global_options[0] = self.global_options[0] & ~self.name_map[name]
if name == 'degBound':
global Kstd1_deg
Kstd1_deg = value
elif name == 'multBound':
global Kstd1_mu
Kstd1_mu = value
except KeyError:
raise NameError("Option '%s' unknown."%(name,))
def __int__(self):
"""
EXAMPLE::
sage: from sage.libs.singular.option import opt
sage: hex(int(opt))
'0x6000082'
"""
return int(self.global_options[0])
def save(self):
"""
Return a triple of integers that allow reconstruction of the options.
EXAMPLE::
sage: from sage.libs.singular.option import opt
sage: opt['deg_bound']
0
sage: opt['red_tail']
True
sage: s = opt.save()
sage: opt['deg_bound'] = 2
sage: opt['red_tail'] = False
sage: opt['deg_bound']
2
sage: opt['red_tail']
False
sage: opt.load(s)
sage: opt['deg_bound']
0
sage: opt['red_tail']
True
sage: opt.reset_default() # needed to avoid side effects
"""
return (int(self.global_options[0]), self['deg_bound'], self['mult_bound'])
def load(self, value=None):
"""
EXAMPLE::
sage: from sage.libs.singular.option import opt as sopt
sage: bck = sopt.save(); hex(bck[0]), bck[1], bck[2]
('0x6000082', 0, 0)
sage: sopt['redTail'] = False
sage: hex(int(sopt))
'0x4000082'
sage: sopt.load(bck)
sage: sopt['redTail']
True
"""
if value == None:
value = (None,0,0)
self.global_options[0] = int(value[0])
global Kstd1_deg
global Kstd1_mu
Kstd1_deg = value[1]
Kstd1_mu = value[2]
def __repr__(self):
"""
EXAMPLE::
sage: from sage.libs.singular.option import opt as sopt
sage: sopt
general options for libSingular (current value 0x06000082)
"""
return "%s options for libSingular (current value 0x%08x)"%(self.name, self.global_options[0])
cdef class LibSingularOptions(LibSingularOptions_abstract):
"""
Pythonic Interface to libSingular's options.
Supported options are:
- ``return_sb`` or ``returnSB`` - the functions ``syz``,
``intersect``, ``quotient``, ``modulo`` return a standard
base instead of a generating set if ``return_sb``
is set. This option should not be used for ``lift``.
- ``fast_hc`` or ``fastHC`` - tries to find the highest corner
of the staircase (HC) as fast as possible during a standard
basis computation (only used for local orderings).
- ``int_strategy`` or ``intStrategy`` - avoids division of
coefficients during standard basis computations. This option
is ring dependent. By default, it is set for rings with
characteristic 0 and not set for all other rings.
- ``lazy`` - uses a more lazy approach in std computations, which
was used in SINGULAR version before 2-0 (and which may lead to
faster or slower computations, depending on the example).
- ``length`` - select shorter reducers in std computations.
- ``not_regularity`` or ``notRegularity`` - disables the
regularity bound for ``res`` and ``mres``.
- ``not_sugar`` or ``notSugar`` - disables the sugar strategy
during standard basis computation.
- ``not_buckets`` or ``notBuckets`` - disables the bucket
representation of polynomials during standard basis
computations. This option usually decreases the memory
usage but increases the computation time. It should only
be set for memory-critical standard basis computations.
- ``old_std`` or ``oldStd`` - uses a more lazy approach in std
computations, which was used in SINGULAR version before 2-0
(and which may lead to faster or slower computations, depending
on the example).
- ``prot`` - shows protocol information indicating the progress
during the following computations: ``facstd``, ``fglm``,
``groebner``, ``lres``, ``mres``, ``minres``, ``mstd``,
``res``, ``slimgb``, ``sres``, ``std``, ``stdfglm``,
``stdhilb``, ``syz``.
- `red_sb`` or ``redSB`` - computes a reduced standard basis in
any standard basis computation.
- ``red_tail`` or ``redTail`` - reduction of the tails of
polynomials during standard basis computations. This option
is ring dependent. By default, it is set for rings with global
degree orderings and not set for all other rings.
- ``red_through`` or ``redThrough`` - for inhomogenous input,
polynomial reductions during standard basis computations are
never postponed, but always finished through. This option is
ring dependent. By default, it is set for rings with global
degree orderings and not set for all other rings.
- ``sugar_crit`` or ``sugarCrit`` - uses criteria similar to the
homogeneous case to keep more useless pairs.
- ``weight_m`` or ``weightM`` - automatically computes suitable
weights for the weighted ecart and the weighted sugar method.
In addition, two integer valued parameters are supported, namely:
- ``deg_bound`` or ``degBound`` - The standard basis computation
is stopped if the total (weighted) degree exceeds ``deg_bound``.
``deg_bound`` should not be used for a global ordering with
inhomogeneous input. Reset this bound by setting ``deg_bound``
to 0. The exact meaning of "degree" depends on the ring odering
and the command: ``slimgb`` uses always the total degree with
weights 1, ``std`` does so for block orderings, only.
- ``mult_bound`` or ``multBound`` - The standard basis computation
is stopped if the ideal is zero-dimensional in a ring with local
ordering and its multiplicity is lower than ``mult_bound``.
Reset this bound by setting ``mult_bound`` to 0.
EXAMPLE::
sage: from sage.libs.singular.option import LibSingularOptions
sage: libsingular_options = LibSingularOptions()
sage: libsingular_options
general options for libSingular (current value 0x06000082)
Here we demonstrate the intended way of using libSingular options::
sage: R.<x,y> = QQ[]
sage: I = R*[x^3+y^2,x^2*y+1]
sage: I.groebner_basis(deg_bound=2)
[x^3 + y^2, x^2*y + 1]
sage: I.groebner_basis()
[x^3 + y^2, x^2*y + 1, y^3 - x]
The option ``mult_bound`` is only relevant in the local case::
sage: Rlocal.<x,y,z> = PolynomialRing(QQ, order='ds')
sage: x^2<x
True
sage: J = [x^7+y^7+z^6,x^6+y^8+z^7,x^7+y^5+z^8, x^2*y^3+y^2*z^3+x^3*z^2,x^3*y^2+y^3*z^2+x^2*z^3]*Rlocal
sage: J.groebner_basis(mult_bound=100)
[x^3*y^2 + y^3*z^2 + x^2*z^3, x^2*y^3 + x^3*z^2 + y^2*z^3, y^5, x^6 + x*y^4*z^5, x^4*z^2 - y^4*z^2 - x^2*y*z^3 + x*y^2*z^3, z^6 - x*y^4*z^4 - x^3*y*z^5]
sage: J.groebner_basis()
[x^3*y^2 + y^3*z^2 + x^2*z^3, x^2*y^3 + x^3*z^2 + y^2*z^3, y^5, x^6, x^4*z^2 - y^4*z^2 - x^2*y*z^3 + x*y^2*z^3, z^6, y^4*z^3 - y^3*z^4 - x^2*z^5, x^3*y*z^4 - x^2*y^2*z^4 + x*y^3*z^4, x^3*z^5, x^2*y*z^5 + y^3*z^5, x*y^3*z^5]
"""
def __init__(self, **kwds):
"""
Create a new option interface.
EXAMPLE::
sage: from sage.libs.singular.option import LibSingularOptions
sage: libsingular_options = LibSingularOptions()
sage: libsingular_options
general options for libSingular (current value 0x06000082)
"""
self.global_options = &singular_options
self.name = "general"
self.name_map = {"prot": Sy_bit(OPT_PROT),
"redSB": Sy_bit(OPT_REDSB),
"notBuckets": Sy_bit(OPT_NOT_BUCKETS),
"notSugar": Sy_bit(OPT_NOT_SUGAR),
"sugarCrit": Sy_bit(OPT_SUGARCRIT),
"redThrough": Sy_bit(OPT_REDTHROUGH),
"returnSB": Sy_bit(OPT_RETURN_SB),
"fastHC": Sy_bit(OPT_FASTHC),
"oldStd": Sy_bit(OPT_OLDSTD),
"redTail": Sy_bit(OPT_REDTAIL),
"intStrategy": Sy_bit(OPT_INTSTRATEGY),
"notRegularity": Sy_bit(OPT_NOTREGULARITY),
"weightM": Sy_bit(OPT_WEIGHTM),
"degBound": Sy_bit(OPT_DEGBOUND),
"multBound": Sy_bit(OPT_MULTBOUND)}
LibSingularOptions_abstract.__init__(self, **kwds)
def reset_default(self):
"""
Reset libSingular's default options.
EXAMPLE::
sage: from sage.libs.singular.option import opt
sage: opt['red_tail']
True
sage: opt['red_tail'] = False
sage: opt['red_tail']
False
sage: opt['deg_bound']
0
sage: opt['deg_bound'] = 2
sage: opt['deg_bound']
2
sage: opt.reset_default()
sage: opt['red_tail']
True
sage: opt['deg_bound']
0
"""
from sage.libs.singular.singular import _saved_options
self.load(_saved_options)
cdef class LibSingularVerboseOptions(LibSingularOptions_abstract):
"""
Pythonic Interface to libSingular's verbosity options.
Supported options are:
- ``mem`` - shows memory usage in square brackets.
- ``yacc`` - Only available in debug version.
- ``redefine`` - warns about variable redefinitions.
- ``reading`` - shows the number of characters read from a file.
- ``loadLib`` or ``load_lib`` - shows loading of libraries.
- ``debugLib`` or ``debug_lib`` - warns about syntax errors
when loading a library.
- ``loadProc`` or ``load_proc`` - shows loading of procedures
from libraries.
- ``defRes`` or ``def_res`` - shows the names of the syzygy
modules while converting ``resolution`` to ``list``.
- ``usage`` - shows correct usage in error messages.
- ``Imap`` or ``imap`` - shows the mapping of variables with
the ``fetch`` and ``imap`` commands.
- ``notWarnSB`` or ``not_warn_sb`` - do not warn if
a basis is not a standard basis
- ``contentSB`` or ``content_sb`` - avoids to divide by the
content of a polynomial in ``std`` and related algorithms.
Should usually not be used.
- ``cancelunit`` - avoids to divide polynomials by non-constant
units in ``std`` in the local case. Should usually not be used.
EXAMPLE::
sage: from sage.libs.singular.option import LibSingularVerboseOptions
sage: libsingular_verbose = LibSingularVerboseOptions()
sage: libsingular_verbose
verbosity options for libSingular (current value 0x00002851)
"""
def __init__(self, **kwds):
"""
Create a new option interface.
EXAMPLE::
sage: from sage.libs.singular.option import LibSingularVerboseOptions
sage: libsingular_verb_options = LibSingularVerboseOptions()
sage: libsingular_verb_options
verbosity options for libSingular (current value 0x00002851)
"""
self.global_options = &singular_verbose_options
self.name = "verbosity"
self.name_map = {"mem": Sy_bit(V_SHOW_MEM),
"yacc": Sy_bit(V_YACC),
"redefine": Sy_bit(V_REDEFINE),
"reading": Sy_bit(V_READING),
"loadLib": Sy_bit(V_LOAD_LIB),
"debugLib": Sy_bit(V_DEBUG_LIB),
"loadProc": Sy_bit(V_LOAD_PROC),
"defRes": Sy_bit(V_DEF_RES),
"usage": Sy_bit(V_SHOW_USE),
"Imap": Sy_bit(V_IMAP),
"prompt": Sy_bit(V_PROMPT),
"notWarnSB":Sy_bit(V_NSB),
"contentSB":Sy_bit(V_CONTENTSB),
"cancelunit":Sy_bit(V_CANCELUNIT),
}
LibSingularOptions_abstract.__init__(self, **kwds)
def reset_default(self):
"""
Return to libSingular's default verbosity options
EXAMPLE::
sage: from sage.libs.singular.option import opt_verb
sage: opt_verb['not_warn_sb']
False
sage: opt_verb['not_warn_sb'] = True
sage: opt_verb['not_warn_sb']
True
sage: opt_verb.reset_default()
sage: opt_verb['not_warn_sb']
False
"""
from sage.libs.singular.singular import _saved_verbose_options
self.global_options[0] = int(_saved_verbose_options)
cdef class LibSingularOptionsContext:
"""
Option context
This object localizes changes to options.
EXAMPLE::
sage: from sage.libs.singular.option import opt, opt_ctx
sage: opt
general options for libSingular (current value 0x06000082)
::
sage: with opt_ctx(redTail=False):
... print opt
... with opt_ctx(redThrough=False):
... print opt
...
general options for libSingular (current value 0x04000082)
general options for libSingular (current value 0x04000002)
sage: print opt
general options for libSingular (current value 0x06000082)
"""
cdef list bck
cdef list bck_degBound
cdef list bck_multBound
cdef public LibSingularOptions_abstract opt
cdef object options
def __init__(self, LibSingularOptions_abstract opt, **kwds):
"""
Create a new context.
EXAMPLE::
sage: from sage.libs.singular.option import LibSingularOptionsContext, opt
sage: LibSingularOptionsContext(opt)
general options context for libSingular
"""
self.bck = []
self.bck_degBound = []
self.bck_multBound = []
self.options = kwds
self.opt = opt
def __enter__(self):
"""
EXAMPLE::
sage: from sage.libs.singular.option import opt, opt_ctx
sage: opt['redTail']
True
sage: with opt_ctx(redTail=False):
... opt['redTail']
False
"""
self.bck.append(self.opt.global_options[0])
self.bck_degBound.append(Kstd1_deg)
self.bck_multBound.append(Kstd1_mu)
opt = self.opt.__class__()
for k,v in self.options.iteritems():
opt[k] = v
def __call__(self, **kwds):
"""
Return a new option context where ``**kwds`` are applied.
EXAMPLE::
sage: from sage.libs.singular.option import opt, opt_ctx
sage: opt['redTail']
True
sage: with opt_ctx(redTail=False):
... opt['redTail']
False
"""
new = self.__class__(self.opt, **kwds)
return new
def __exit__(self, typ, value, tb):
"""
EXAMPLE::
sage: from sage.libs.singular.option import opt, opt_ctx
sage: opt['redTail']
True
sage: with opt_ctx(redTail=False):
... opt['redTail']
False
"""
self.opt.global_options[0] = self.bck.pop()
global Kstd1_deg
global Kstd1_mu
Kstd1_deg = self.bck_degBound.pop()
Kstd1_mu = self.bck_multBound.pop()
def __repr__(self):
"""
EXAMPLE::
sage: from sage.libs.singular.option import opt_ctx
sage: opt_ctx
general options context for libSingular
"""
return "%s options context for libSingular"%(self.opt.name)
opt = LibSingularOptions()
opt.reset_default()
opt_verb = LibSingularVerboseOptions()
opt_verb.reset_default()
opt_ctx = LibSingularOptionsContext(opt)
opt_verb_ctx = LibSingularOptionsContext(opt_verb)
