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""" 

Vectors with integer entries 

  

AUTHOR: 

  

- William Stein (2007) 

  

EXAMPLES:: 

  

sage: v = vector(ZZ,[1,2,3,4,5]) 

sage: v 

(1, 2, 3, 4, 5) 

sage: 3*v 

(3, 6, 9, 12, 15) 

sage: v*7 

(7, 14, 21, 28, 35) 

sage: -v 

(-1, -2, -3, -4, -5) 

sage: v - v 

(0, 0, 0, 0, 0) 

sage: v + v 

(2, 4, 6, 8, 10) 

sage: v * v # dot product. 

55 

  

We make a large zero vector:: 

  

sage: k = ZZ^100000; k 

Ambient free module of rank 100000 over the principal ideal domain Integer Ring 

sage: v = k(0) 

sage: v[:10] 

(0, 0, 0, 0, 0, 0, 0, 0, 0, 0) 

  

TESTS:: 

  

sage: v = vector(ZZ, [1,2,3,4]) 

sage: loads(dumps(v)) == v 

True 

  

sage: w = vector(ZZ, [-1,0,0,0]) 

sage: w.set_immutable() 

sage: isinstance(hash(w), int) 

True 

""" 

  

#***************************************************************************** 

# Copyright (C) 2007 William Stein <wstein@gmail.com> 

# 

# This program is free software: you can redistribute it and/or modify 

# it under the terms of the GNU General Public License as published by 

# the Free Software Foundation, either version 2 of the License, or 

# (at your option) any later version. 

# http://www.gnu.org/licenses/ 

#***************************************************************************** 

from __future__ import absolute_import 

  

from cysignals.memory cimport check_allocarray, sig_free 

from cysignals.signals cimport sig_on, sig_off 

  

from sage.structure.element cimport Element, ModuleElement, RingElement, Vector 

  

from sage.rings.integer cimport Integer 

  

cimport sage.modules.free_module_element as free_module_element 

  

from .free_module_element import vector 

  

from sage.libs.gmp.mpz cimport * 

  

  

cdef inline _Integer_from_mpz(mpz_t e): 

cdef Integer z = Integer.__new__(Integer) 

mpz_set(z.value, e) 

return z 

  

cdef class Vector_integer_dense(free_module_element.FreeModuleElement): 

cdef bint is_dense_c(self): 

return 1 

cdef bint is_sparse_c(self): 

return 0 

  

def __copy__(self): 

cdef Vector_integer_dense y 

y = self._new_c() 

cdef Py_ssize_t i 

for i in range(self._degree): 

mpz_set(y._entries[i], self._entries[i]) 

return y 

  

cdef int _init(self, Py_ssize_t degree, Parent parent) except -1: 

""" 

Initialize the C data structures in this vector. After calling 

this, ``self`` is a zero vector of degree ``degree`` with 

parent ``parent``. 

  

Only if you call ``__new__`` without a ``parent`` argument, it 

is needed to call this function manually. The only reason to do 

that is for efficiency: calling ``__new__`` without any 

additional arguments besides the type and then calling ``_init`` 

is (slightly) more efficient than calling ``__new__`` with a 

``parent`` argument. 

""" 

# Assign variables only when the array is fully initialized 

cdef mpz_t* entries = <mpz_t*>check_allocarray(degree, sizeof(mpz_t)) 

cdef Py_ssize_t i 

sig_on() 

for i in range(degree): 

mpz_init(entries[i]) 

sig_off() 

self._entries = entries 

self._degree = degree 

self._parent = parent 

  

def __cinit__(self, parent=None, x=None, coerce=True, copy=True): 

self._entries = NULL 

self._is_mutable = 1 

if parent is None: 

self._degree = 0 

return 

self._init(parent.degree(), <Parent?>parent) 

  

def __init__(self, parent, x, coerce=True, copy=True): 

cdef Py_ssize_t i 

cdef Integer z 

if isinstance(x, (list, tuple)): 

if len(x) != self._degree: 

raise TypeError("x must be a list of the right length") 

for i from 0 <= i < self._degree: 

z = Integer(x[i]) 

mpz_set(self._entries[i], z.value) 

return 

if x != 0: 

raise TypeError("can't initialize vector from nonzero non-list") 

  

def __dealloc__(self): 

cdef Py_ssize_t i 

if self._entries: 

for i in range(self._degree): 

mpz_clear(self._entries[i]) 

sig_free(self._entries) 

  

cpdef int _cmp_(left, right) except -2: 

""" 

EXAMPLES:: 

  

sage: v = vector(ZZ, [0,0,0,0]) 

sage: v == 0 

True 

sage: v == 1 

False 

sage: v == v 

True 

sage: w = vector(ZZ, [-1,0,0,0]) 

sage: w == w 

True 

sage: w < v 

True 

sage: w > v 

False 

""" 

cdef Py_ssize_t i 

cdef int c 

for i from 0 <= i < left.degree(): 

c = mpz_cmp(left._entries[i], (<Vector_integer_dense>right)._entries[i]) 

if c < 0: 

return -1 

elif c > 0: 

return 1 

return 0 

  

cdef get_unsafe(self, Py_ssize_t i): 

""" 

EXAMPLES:: 

  

sage: v = vector([1,2,3]); v 

(1, 2, 3) 

sage: v[0] 

1 

sage: v[-2] 

2 

sage: v[0:2] 

(1, 2) 

sage: v[::-1] 

(3, 2, 1) 

""" 

cdef Integer z = Integer.__new__(Integer) 

mpz_set(z.value, self._entries[i]) 

return z 

  

cdef int set_unsafe(self, Py_ssize_t i, value) except -1: 

""" 

EXAMPLES:: 

  

sage: v = vector([1,2,3]); v 

(1, 2, 3) 

sage: v[0] = 2 

sage: v[1:3] = [1, 4]; v 

(2, 1, 4) 

""" 

mpz_set(self._entries[i], (<Integer>value).value) 

  

def list(self,copy=True): 

""" 

The list of entries of the vector. 

  

INPUT: 

  

- ``copy``, ignored optional argument. 

  

EXAMPLES:: 

  

sage: v = vector([1,2,3,4]) 

sage: a = v.list(copy=False); a 

[1, 2, 3, 4] 

sage: a[0] = 0 

sage: v 

(1, 2, 3, 4) 

""" 

cdef int i 

return [_Integer_from_mpz(self._entries[i]) for i in 

xrange(self._degree)] 

  

def __reduce__(self): 

return (unpickle_v1, (self._parent, self.list(), self._degree, self._is_mutable)) 

  

cpdef _add_(self, right): 

cdef Vector_integer_dense z, r 

r = right 

z = self._new_c() 

cdef Py_ssize_t i 

for i in range(self._degree): 

mpz_add(z._entries[i], self._entries[i], r._entries[i]) 

return z 

  

  

cpdef _sub_(self, right): 

cdef Vector_integer_dense z, r 

r = right 

z = self._new_c() 

cdef Py_ssize_t i 

for i in range(self._degree): 

mpz_sub(z._entries[i], self._entries[i], r._entries[i]) 

return z 

  

cpdef _dot_product_(self, Vector right): 

""" 

Dot product of dense vectors over the integers. 

  

EXAMPLES:: 

  

sage: v = vector(ZZ, [1,2,-3]); w = vector(ZZ,[4,3,2]) 

sage: v*w 

4 

sage: w*v 

4 

""" 

cdef Vector_integer_dense r = right 

cdef Integer z = Integer.__new__(Integer) 

cdef mpz_t t 

mpz_init(t) 

mpz_set_si(z.value, 0) 

cdef Py_ssize_t i 

for i in range(self._degree): 

mpz_mul(t, self._entries[i], r._entries[i]) 

mpz_add(z.value, z.value, t) 

mpz_clear(t) 

return z 

  

cpdef _pairwise_product_(self, Vector right): 

""" 

EXAMPLES:: 

  

sage: v = vector(ZZ, [1,2,-3]); w = vector(ZZ,[4,3,2]) 

sage: v.pairwise_product(w) 

(4, 6, -6) 

""" 

cdef Vector_integer_dense z, r 

r = right 

z = self._new_c() 

cdef Py_ssize_t i 

for i in range(self._degree): 

mpz_mul(z._entries[i], self._entries[i], r._entries[i]) 

return z 

  

cpdef _rmul_(self, Element left): 

cdef Vector_integer_dense z 

cdef Integer a 

a = left 

z = self._new_c() 

cdef Py_ssize_t i 

for i in range(self._degree): 

mpz_mul(z._entries[i], self._entries[i], a.value) 

return z 

  

cpdef _lmul_(self, Element right): 

cdef Vector_integer_dense z 

cdef Integer a 

a = right 

z = self._new_c() 

cdef Py_ssize_t i 

for i in range(self._degree): 

mpz_mul(z._entries[i], self._entries[i], a.value) 

return z 

  

cpdef _neg_(self): 

cdef Vector_integer_dense z 

z = self._new_c() 

cdef Py_ssize_t i 

for i in range(self._degree): 

mpz_neg(z._entries[i], self._entries[i]) 

return z 

  

def _singular_(self, singular=None): 

r""" 

Return \Singular representation of this integer vector. 

  

INPUT: 

  

- singular -- \Singular interface instance (default: None) 

  

EXAMPLES:: 

  

sage: A = random_matrix(ZZ,1,3) 

sage: v = A.row(0) 

sage: vs = singular(v); vs 

-8, 

2, 

0 

sage: vs.type() 

'intvec' 

""" 

if singular is None: 

from sage.interfaces.singular import singular as singular_default 

singular = singular_default 

  

name = singular._next_var_name() 

values = str(self.list())[1:-1] 

singular.eval("intvec %s = %s"%(name, values)) 

  

from sage.interfaces.singular import SingularElement 

return SingularElement(singular, 'foobar', name, True) 

  

def unpickle_v0(parent, entries, degree): 

# If you think you want to change this function, don't. 

# Instead make a new version with a name like 

# make_FreeModuleElement_generic_dense_v1 

# and changed the reduce method below. 

cdef Vector_integer_dense v 

v = Vector_integer_dense.__new__(Vector_integer_dense) 

v._init(degree, parent) 

cdef Integer z 

cdef Py_ssize_t i 

for i in range(degree): 

z = Integer(entries[i]) 

mpz_set(v._entries[i], z.value) 

return v 

  

def unpickle_v1(parent, entries, degree, is_mutable): 

cdef Vector_integer_dense v 

v = Vector_integer_dense.__new__(Vector_integer_dense) 

v._init(degree, parent) 

cdef Integer z 

cdef Py_ssize_t i 

for i in range(degree): 

z = Integer(entries[i]) 

mpz_set(v._entries[i], z.value) 

v._is_mutable = is_mutable 

return v