Interface to Macaulay2¶

Note

You must have Macaulay2 installed on your computer for this interface to work. Macaulay2 is not included with Sage, but you can obtain it from https://macaulay2.com/. No additional optional Sage packages are required.

Sage provides an interface to the Macaulay2 computational algebra system. This system provides extensive functionality for commutative algebra. You do not have to install any optional packages.

The Macaulay2 interface offers three pieces of functionality:

macaulay2_console() – a function that dumps you into an interactive command-line Macaulay2 session
macaulay2.eval(expr) – evaluation of arbitrary Macaulay2 expressions, with the result returned as a string
macaulay2(expr) – creation of a Sage object that wraps a Macaulay2 object. This provides a Pythonic interface to Macaulay2. For example, if f = macaulay2(10), then f.gcd(25) returns the GCD of \(10\) and \(25\) computed using Macaulay2.

EXAMPLES:

Sage

sage: macaulay2('3/5 + 7/11')
68
--
55
sage: f = macaulay2('f = i -> i^3')
sage: f
f
sage: f(5)
125

sage: R = macaulay2('ZZ/5[x,y,z]')
sage: R
ZZ
--[x...z]
 5
sage: x = macaulay2('x')
sage: y = macaulay2('y')
sage: (x+y)^5
 5    5
x  + y
sage: parent((x+y)^5)
Macaulay2

Python

>>> from sage.all import *
>>> macaulay2('3/5 + 7/11')
68
--
55
>>> f = macaulay2('f = i -> i^3')
>>> f
f
>>> f(Integer(5))
125

>>> R = macaulay2('ZZ/5[x,y,z]')
>>> R
ZZ
--[x...z]
 5
>>> x = macaulay2('x')
>>> y = macaulay2('y')
>>> (x+y)**Integer(5)
 5    5
x  + y
>>> parent((x+y)**Integer(5))
Macaulay2

The name of the variable to which a Macaulay2 element is assigned internally can be passed as an argument. This is useful for types like polynomial rings which acquire that name in Macaulay2:

Sage

sage: R = macaulay2('QQ[x,y,z,w]', 'R')
sage: R
R

sage: f = macaulay2('x^4 + 2*x*y^3 + x*y^2*w + x*y*z*w + x*y*w^2'
....:               '+ 2*x*z*w^2 + y^4 + y^3*w + 2*y^2*z*w + z^4 + w^4')
sage: f
 4       3    4    4      2     3                2           2         2    4
x  + 2x*y  + y  + z  + x*y w + y w + x*y*z*w + 2y z*w + x*y*w  + 2x*z*w  + w
sage: g = f * macaulay2('x+y^5')
sage: print(g.factor())
  4       3    4    4      2     3                2           2         2    4   5
(x  + 2x*y  + y  + z  + x*y w + y w + x*y*z*w + 2y z*w + x*y*w  + 2x*z*w  + w )(y  + x)

Python

>>> from sage.all import *
>>> R = macaulay2('QQ[x,y,z,w]', 'R')
>>> R
R

>>> f = macaulay2('x^4 + 2*x*y^3 + x*y^2*w + x*y*z*w + x*y*w^2'
...               '+ 2*x*z*w^2 + y^4 + y^3*w + 2*y^2*z*w + z^4 + w^4')
>>> f
 4       3    4    4      2     3                2           2         2    4
x  + 2x*y  + y  + z  + x*y w + y w + x*y*z*w + 2y z*w + x*y*w  + 2x*z*w  + w
>>> g = f * macaulay2('x+y^5')
>>> print(g.factor())
  4       3    4    4      2     3                2           2         2    4   5
(x  + 2x*y  + y  + z  + x*y w + y w + x*y*z*w + 2y z*w + x*y*w  + 2x*z*w  + w )(y  + x)

Use eval() for explicit control over what is sent to the interpreter. The argument is evaluated in Macaulay2 as is:

Sage

sage: macaulay2.eval('compactMatrixForm')
true
sage: macaulay2.eval('compactMatrixForm = false;')
sage: macaulay2.eval('matrix {{1, x^2+y}}')
|      2      |
|  1  x  + y  |

        1      2
Matrix R  <-- R
sage: macaulay2.eval('compactMatrixForm = true;')

Python

>>> from sage.all import *
>>> macaulay2.eval('compactMatrixForm')
true
>>> macaulay2.eval('compactMatrixForm = false;')
>>> macaulay2.eval('matrix {{1, x^2+y}}')
|      2      |
|  1  x  + y  |
<BLANKLINE>
        1      2
Matrix R  <-- R
>>> macaulay2.eval('compactMatrixForm = true;')

AUTHORS:

Kiran Kedlaya and David Roe (2006-02-05, during Sage coding sprint)
William Stein (2006-02-09): inclusion in Sage; prompt uses regexp, calling of Macaulay2 functions via __call__.
William Stein (2006-02-09): fixed bug in reading from file and improved output cleaning.
Kiran Kedlaya (2006-02-12): added ring and ideal constructors, list delimiters, is_Macaulay2Element, sage_polystring, __floordiv__, __mod__, __iter__, __len__; stripped extra leading space and trailing newline from output.

Todo

Get rid of all numbers in output, e.g., in ideal function below.

class sage.interfaces.macaulay2.Macaulay2(maxread=None, script_subdirectory=None, logfile=None, server=None, server_tmpdir=None, command=None)[source]¶

Bases: ExtraTabCompletion, Expect

Interface to the Macaulay2 interpreter.

clear(var)[source]¶

Clear the variable named var.

The interface automatically clears Macaulay2 elements when they fall out of use, so calling this method is usually not necessary.

EXAMPLES:

Sage

sage: macaulay2.eval('R = QQ[x,y];')
sage: macaulay2.eval('net class R')
PolynomialRing
sage: macaulay2.clear('R')
sage: macaulay2.eval('net class R')
Symbol

Python

>>> from sage.all import *
>>> macaulay2.eval('R = QQ[x,y];')
>>> macaulay2.eval('net class R')
PolynomialRing
>>> macaulay2.clear('R')
>>> macaulay2.eval('net class R')
Symbol

console()[source]¶

Spawn a new M2 command-line session.

EXAMPLES:

Sage

sage: macaulay2.console()                    # not tested
Macaulay 2, version 1.1
with packages: Classic, Core, Elimination, IntegralClosure, LLLBases, Parsing, PrimaryDecomposition, SchurRings, TangentCone
...

Python

>>> from sage.all import *
>>> macaulay2.console()                    # not tested
Macaulay 2, version 1.1
with packages: Classic, Core, Elimination, IntegralClosure, LLLBases, Parsing, PrimaryDecomposition, SchurRings, TangentCone
...

cputime(t=None)[source]¶

EXAMPLES:

Sage

sage: R = macaulay2("QQ[x,y]")
sage: x,y = R.gens()
sage: a = (x+y+1)^20
sage: macaulay2.cputime()       # random
0.48393700000000001

Python

>>> from sage.all import *
>>> R = macaulay2("QQ[x,y]")
>>> x,y = R.gens()
>>> a = (x+y+Integer(1))**Integer(20)
>>> macaulay2.cputime()       # random
0.48393700000000001

eval(code, strip=True, **kwds)[source]¶

Send the code x to the Macaulay2 interpreter and return the output as a string suitable for input back into Macaulay2, if possible.

INPUT:

code – string
strip – ignored

EXAMPLES:

Sage

sage: macaulay2.eval("2+2")
4

Python

>>> from sage.all import *
>>> macaulay2.eval("2+2")
4

get(var)[source]¶

Get the value of the variable var.

INPUT:

var – string; the name of the variable in Macaulay2

OUTPUT: string of the textual representation of the variable in Macaulay2

EXAMPLES:

Sage

sage: macaulay2.set("a", "2")
sage: macaulay2.get("a")
2

Python

>>> from sage.all import *
>>> macaulay2.set("a", "2")
>>> macaulay2.get("a")
2

Note that the following syntax is used to obtain a Macaulay2Element instead:

Sage

sage: a = macaulay2('2'); a
2
sage: type(a)
<class 'sage.interfaces.macaulay2.Macaulay2Element'>

Python

>>> from sage.all import *
>>> a = macaulay2('2'); a
2
>>> type(a)
<class 'sage.interfaces.macaulay2.Macaulay2Element'>

help(s)[source]¶

EXAMPLES:

Sage

sage: macaulay2.help("load")  # 1st call might be chatty
...
sage: macaulay2.help("load")
load...
****...
...
  * "input" -- read Macaulay2 commands and echo
  * "notify" -- whether to notify the user when a file is loaded...

Python

>>> from sage.all import *
>>> macaulay2.help("load")  # 1st call might be chatty
...
>>> macaulay2.help("load")
load...
****...
...
  * "input" -- read Macaulay2 commands and echo
  * "notify" -- whether to notify the user when a file is loaded...

ideal(*gens)[source]¶

Return the ideal generated by gens.

INPUT:

gens – list or tuple of Macaulay2 objects (or objects that can be made into Macaulay2 objects via evaluation)

OUTPUT: the Macaulay2 ideal generated by the given list of gens

EXAMPLES:

Sage

sage: R2 = macaulay2.ring('QQ', '[x, y]'); R2
QQ[x...y]
sage: I = macaulay2.ideal( ('y^2 - x^3', 'x - y') ); I
          3    2
ideal (- x  + y , x - y)
sage: J = I^3; J.gb().gens().transpose()
{-9} | y9-3y8+3y7-y6             |
{-7} | xy6-2xy5+xy4-y7+2y6-y5    |
{-5} | x2y3-x2y2-2xy4+2xy3+y5-y4 |
{-3} | x3-3x2y+3xy2-y3           |

Python

>>> from sage.all import *
>>> R2 = macaulay2.ring('QQ', '[x, y]'); R2
QQ[x...y]
>>> I = macaulay2.ideal( ('y^2 - x^3', 'x - y') ); I
          3    2
ideal (- x  + y , x - y)
>>> J = I**Integer(3); J.gb().gens().transpose()
{-9} | y9-3y8+3y7-y6             |
{-7} | xy6-2xy5+xy4-y7+2y6-y5    |
{-5} | x2y3-x2y2-2xy4+2xy3+y5-y4 |
{-3} | x3-3x2y+3xy2-y3           |

new_from(type, value)[source]¶

Return a new Macaulay2Element of type type constructed from value.

EXAMPLES:

Sage

sage: l = macaulay2.new_from("MutableList", [1,2,3])
sage: l
MutableList{...3...}
sage: list(l)
[1, 2, 3]

Python

>>> from sage.all import *
>>> l = macaulay2.new_from("MutableList", [Integer(1),Integer(2),Integer(3)])
>>> l
MutableList{...3...}
>>> list(l)
[1, 2, 3]

options = Current options for Macaulay2 - after_print: False[source]¶

restart()[source]¶: Restart Macaulay2 interpreter.

ring(base_ring='ZZ', vars='[x]', order='Lex')[source]¶

Create a Macaulay2 polynomial ring.

INPUT:

base_ring – base ring (see examples below)
vars – tuple or string that defines the variable names
order – string (default: 'Lex'); the monomial order

OUTPUT: a Macaulay2 ring

EXAMPLES:

This is a ring in variables named a through d over the finite field of order 7, with graded reverse lex ordering:

Sage

sage: R1 = macaulay2.ring('ZZ/7', '[a..d]', 'GRevLex')
sage: R1.describe()
ZZ
--[a..d, Degrees => {4:1}, Heft => {1}, MonomialOrder => {MonomialSize => 16}]
 7                                                       {GRevLex => {4:1}  }
                                                         {Position => Up    }
sage: R1.char()
7

Python

>>> from sage.all import *
>>> R1 = macaulay2.ring('ZZ/7', '[a..d]', 'GRevLex')
>>> R1.describe()
ZZ
--[a..d, Degrees => {4:1}, Heft => {1}, MonomialOrder => {MonomialSize => 16}]
 7                                                       {GRevLex => {4:1}  }
                                                         {Position => Up    }
>>> R1.char()
7

This is a polynomial ring over the rational numbers:

Sage

sage: R2 = macaulay2.ring('QQ', '[x, y]')
sage: R2.describe()
QQ[x..y, Degrees => {2:1}, Heft => {1}, MonomialOrder => {MonomialSize => 16}]
                                                         {Lex => 2          }
                                                         {Position => Up    }

Python

>>> from sage.all import *
>>> R2 = macaulay2.ring('QQ', '[x, y]')
>>> R2.describe()
QQ[x..y, Degrees => {2:1}, Heft => {1}, MonomialOrder => {MonomialSize => 16}]
                                                         {Lex => 2          }
                                                         {Position => Up    }

set(var, value)[source]¶

Set the variable var to the given value.

INPUT:

var – string; the name of the variable in Macaulay2
value – string to evaluate

EXAMPLES:

Sage

sage: macaulay2.set("a", "1+1")
sage: macaulay2.get("a")
2

Python

>>> from sage.all import *
>>> macaulay2.set("a", "1+1")
>>> macaulay2.get("a")
2

set_seed(seed=None)[source]¶

Set the seed for Macaulay2 interpreter.

INPUT:

seed – number (default: None); if None, it is set to a random number

OUTPUT: the new seed

EXAMPLES:

Sage

sage: m = Macaulay2()
sage: m.set_seed(123456)
123456
sage: [m.random(100) for _ in range(11)]
[8, 29, 5, 22, 4, 32, 35, 57, 3, 95, 36]

Python

>>> from sage.all import *
>>> m = Macaulay2()
>>> m.set_seed(Integer(123456))
123456
>>> [m.random(Integer(100)) for _ in range(Integer(11))]
[8, 29, 5, 22, 4, 32, 35, 57, 3, 95, 36]

use(R)[source]¶

Use the Macaulay2 ring R.

EXAMPLES:

Sage

sage: R = macaulay2("QQ[x,y]")
sage: P = macaulay2("ZZ/7[symbol x, symbol y]")
sage: macaulay2("x").cls()._operator('===', P)
true
sage: macaulay2.use(R)
sage: macaulay2("x").cls()._operator('===', R)
true

Python

>>> from sage.all import *
>>> R = macaulay2("QQ[x,y]")
>>> P = macaulay2("ZZ/7[symbol x, symbol y]")
>>> macaulay2("x").cls()._operator('===', P)
true
>>> macaulay2.use(R)
>>> macaulay2("x").cls()._operator('===', R)
true

version()[source]¶

Return the version of Macaulay2 as a tuple.

EXAMPLES:

Sage

sage: macaulay2.version()
(1, ...)

Python

>>> from sage.all import *
>>> macaulay2.version()
(1, ...)

class sage.interfaces.macaulay2.Macaulay2Element(parent, value, is_name=False, name=None)[source]¶

Bases: ExtraTabCompletion, ExpectElement, Macaulay2Element

Instances of this class represent objects in Macaulay2.

Using the method sage() we can translate some of them to SageMath objects:

_sage_()[source]¶

EXAMPLES:

Sage

sage: macaulay2(ZZ).sage()         # indirect doctest
Integer Ring
sage: macaulay2(QQ).sage()
Rational Field

sage: macaulay2(2).sage()
2
sage: macaulay2(1/2).sage()
1/2
sage: macaulay2(2/1).sage()
2
sage: _.parent()
Rational Field
sage: macaulay2([1,2,3]).sage()
[1, 2, 3]

sage: m = matrix([[1,2],[3,4]])
sage: macaulay2(m).sage()
[1 2]
[3 4]

sage: D = macaulay2('hashTable {4 => 1, 2 => 3}')
sage: D.pairs()
{(4, 1), (2, 3)}
sage: D.sage() == {4: 1, 2: 3}
True

sage: macaulay2(QQ['x,y']).sage()
Multivariate Polynomial Ring in x, y over Rational Field
sage: macaulay2(QQ['x']).sage()
Univariate Polynomial Ring in x over Rational Field
sage: macaulay2(GF(7)['x,y']).sage()
Multivariate Polynomial Ring in x, y over Finite Field of size 7

sage: macaulay2(GF(7)).sage()
Finite Field of size 7
sage: macaulay2(GF(49, 'a')).sage()
Finite Field in a of size 7^2

sage: R.<x,y> = QQ[]
sage: macaulay2(x^2+y^2+1).sage()
x^2 + y^2 + 1

sage: R = macaulay2("QQ[x,y]")
sage: I = macaulay2("ideal (x,y)")
sage: I.sage()
Ideal (x, y) of Multivariate Polynomial Ring in x, y over Rational Field

sage: macaulay2("x = symbol x")
x
sage: macaulay2("QQ[x_0..x_25]").sage()
Multivariate Polynomial Ring in x_0, x_1,..., x_25 over Rational Field

sage: S = ZZ['x,y'].quotient('x^2-y')
sage: macaulay2(S).sage() == S
True
sage: S = GF(101)['x,y'].quotient('x^2-y')
sage: macaulay2(S).sage() == S
True

sage: R = GF(13)['a,b']['c,d']
sage: macaulay2(R).sage() == R
True
sage: macaulay2('a^2 + c').sage() == R('a^2 + c')
True
sage: macaulay2.substitute('a', R).sage().parent() is R
True

sage: R = macaulay2("QQ^2")
sage: R.sage()
Vector space of dimension 2 over Rational Field

sage: macaulay2("vector {4_QQ, 2}").sage()
(4, 2)
sage: _.parent()
Vector space of dimension 2 over Rational Field

sage: m = macaulay2('"hello"')
sage: m.sage()
'hello'

sage: gg = macaulay2.needsPackage('"Graphs"')
sage: g = macaulay2.barbellGraph(3)
sage: g.sage()
Graph on 6 vertices
sage: g.sage().edges(labels=False)
[(0, 1), (0, 2), (1, 2), (2, 3), (3, 4), (3, 5), (4, 5)]

sage: d = 'digraph ({{1,2},{2,1},{3,1}}, EntryMode => "edges")'
sage: g = macaulay2(d)
sage: g.sage()
Digraph on 3 vertices
sage: g.sage().edges(labels=False)
[(1, 2), (2, 1), (3, 1)]

Python

>>> from sage.all import *
>>> macaulay2(ZZ).sage()         # indirect doctest
Integer Ring
>>> macaulay2(QQ).sage()
Rational Field

>>> macaulay2(Integer(2)).sage()
2
>>> macaulay2(Integer(1)/Integer(2)).sage()
1/2
>>> macaulay2(Integer(2)/Integer(1)).sage()
2
>>> _.parent()
Rational Field
>>> macaulay2([Integer(1),Integer(2),Integer(3)]).sage()
[1, 2, 3]

>>> m = matrix([[Integer(1),Integer(2)],[Integer(3),Integer(4)]])
>>> macaulay2(m).sage()
[1 2]
[3 4]

>>> D = macaulay2('hashTable {4 => 1, 2 => 3}')
>>> D.pairs()
{(4, 1), (2, 3)}
>>> D.sage() == {Integer(4): Integer(1), Integer(2): Integer(3)}
True

>>> macaulay2(QQ['x,y']).sage()
Multivariate Polynomial Ring in x, y over Rational Field
>>> macaulay2(QQ['x']).sage()
Univariate Polynomial Ring in x over Rational Field
>>> macaulay2(GF(Integer(7))['x,y']).sage()
Multivariate Polynomial Ring in x, y over Finite Field of size 7

>>> macaulay2(GF(Integer(7))).sage()
Finite Field of size 7
>>> macaulay2(GF(Integer(49), 'a')).sage()
Finite Field in a of size 7^2

>>> R = QQ['x, y']; (x, y,) = R._first_ngens(2)
>>> macaulay2(x**Integer(2)+y**Integer(2)+Integer(1)).sage()
x^2 + y^2 + 1

>>> R = macaulay2("QQ[x,y]")
>>> I = macaulay2("ideal (x,y)")
>>> I.sage()
Ideal (x, y) of Multivariate Polynomial Ring in x, y over Rational Field

>>> macaulay2("x = symbol x")
x
>>> macaulay2("QQ[x_0..x_25]").sage()
Multivariate Polynomial Ring in x_0, x_1,..., x_25 over Rational Field

>>> S = ZZ['x,y'].quotient('x^2-y')
>>> macaulay2(S).sage() == S
True
>>> S = GF(Integer(101))['x,y'].quotient('x^2-y')
>>> macaulay2(S).sage() == S
True

>>> R = GF(Integer(13))['a,b']['c,d']
>>> macaulay2(R).sage() == R
True
>>> macaulay2('a^2 + c').sage() == R('a^2 + c')
True
>>> macaulay2.substitute('a', R).sage().parent() is R
True

>>> R = macaulay2("QQ^2")
>>> R.sage()
Vector space of dimension 2 over Rational Field

>>> macaulay2("vector {4_QQ, 2}").sage()
(4, 2)
>>> _.parent()
Vector space of dimension 2 over Rational Field

>>> m = macaulay2('"hello"')
>>> m.sage()
'hello'

>>> gg = macaulay2.needsPackage('"Graphs"')
>>> g = macaulay2.barbellGraph(Integer(3))
>>> g.sage()
Graph on 6 vertices
>>> g.sage().edges(labels=False)
[(0, 1), (0, 2), (1, 2), (2, 3), (3, 4), (3, 5), (4, 5)]

>>> d = 'digraph ({{1,2},{2,1},{3,1}}, EntryMode => "edges")'
>>> g = macaulay2(d)
>>> g.sage()
Digraph on 3 vertices
>>> g.sage().edges(labels=False)
[(1, 2), (2, 1), (3, 1)]

Chain complexes and maps of chain complexes can be converted:

Sage

sage: R = ZZ['a,b,c']
sage: C = macaulay2(ideal(R.gens())).resolution()
sage: unicode_art(C.sage())
                      ⎛-b  0 -c⎞     ⎛ c⎞
                      ⎜ a -c  0⎟     ⎜ a⎟
          (a b c)     ⎝ 0  b  a⎠     ⎝-b⎠
0 <── C_0 <────── C_1 <───────── C_2 <─── C_3 <── 0
sage: F = C.dot('dd')
sage: G = F.sage()
sage: G.in_degree(2)
[-b  0 -c]
[ a -c  0]
[ 0  b  a]
sage: F.underscore(2).sage() == G.in_degree(2)
True
sage: (F^2).sage()
Chain complex morphism:
  From: Chain complex with at most 4 nonzero terms over Multivariate Polynomial Ring in a, b, c over Integer Ring
  To:   Chain complex with at most 4 nonzero terms over Multivariate Polynomial Ring in a, b, c over Integer Ring

Python

>>> from sage.all import *
>>> R = ZZ['a,b,c']
>>> C = macaulay2(ideal(R.gens())).resolution()
>>> unicode_art(C.sage())
                      ⎛-b  0 -c⎞     ⎛ c⎞
                      ⎜ a -c  0⎟     ⎜ a⎟
          (a b c)     ⎝ 0  b  a⎠     ⎝-b⎠
0 <── C_0 <────── C_1 <───────── C_2 <─── C_3 <── 0
>>> F = C.dot('dd')
>>> G = F.sage()
>>> G.in_degree(Integer(2))
[-b  0 -c]
[ a -c  0]
[ 0  b  a]
>>> F.underscore(Integer(2)).sage() == G.in_degree(Integer(2))
True
>>> (F**Integer(2)).sage()
Chain complex morphism:
  From: Chain complex with at most 4 nonzero terms over Multivariate Polynomial Ring in a, b, c over Integer Ring
  To:   Chain complex with at most 4 nonzero terms over Multivariate Polynomial Ring in a, b, c over Integer Ring

Quotient rings in Macaulay2 inherit variable names from the ambient ring, so we mimic this behaviour in Sage:

Sage

sage: R = macaulay2("ZZ/7[x,y]")
sage: I = macaulay2("ideal (x^3 - y^2)")
sage: (R/I).gens()
{x, y}
sage: (R/I).sage().gens()
(x, y)

Python

>>> from sage.all import *
>>> R = macaulay2("ZZ/7[x,y]")
>>> I = macaulay2("ideal (x^3 - y^2)")
>>> (R/I).gens()
{x, y}
>>> (R/I).sage().gens()
(x, y)

Elements of quotient rings:

Sage

sage: x, y = (R/I).gens()
sage: f = ((x^3 + 2*y^2*x)^7).sage(); f
2*x*y^18 + y^14
sage: f.parent()
Quotient of Multivariate Polynomial Ring in x, y over Finite Field of size 7 by the ideal (x^3 - y^2)

Python

>>> from sage.all import *
>>> x, y = (R/I).gens()
>>> f = ((x**Integer(3) + Integer(2)*y**Integer(2)*x)**Integer(7)).sage(); f
2*x*y^18 + y^14
>>> f.parent()
Quotient of Multivariate Polynomial Ring in x, y over Finite Field of size 7 by the ideal (x^3 - y^2)

after_print_text()[source]¶

Obtain type information for this Macaulay2 element.

This is the text that is displayed using AfterPrint in a Macaulay2 interpreter.

Macaulay2 by default includes this information in the output. In Sage, this behavior can optionally be enabled by setting the option after_print in Macaulay2.options.

EXAMPLES:

Sage

sage: B = macaulay2(matrix([[1, 2], [3, 6]])).kernel(); B
image | 2  |
      | -1 |
sage: B.after_print_text()
                          2
ZZ-module, submodule of ZZ

Python

>>> from sage.all import *
>>> B = macaulay2(matrix([[Integer(1), Integer(2)], [Integer(3), Integer(6)]])).kernel(); B
image | 2  |
      | -1 |
>>> B.after_print_text()
                          2
ZZ-module, submodule of ZZ

cls()[source]¶

Since class is a keyword in Python, we have to use cls to call Macaulay2’s class. In Macaulay2, class corresponds to Sage’s notion of parent.

EXAMPLES:

Sage

sage: macaulay2(ZZ).cls()
Ring

Python

>>> from sage.all import *
>>> macaulay2(ZZ).cls()
Ring

dot(x)[source]¶

EXAMPLES:

Sage

sage: d = macaulay2.new("MutableHashTable")
sage: d["k"] = 4
sage: d.dot("k")
4

Python

>>> from sage.all import *
>>> d = macaulay2.new("MutableHashTable")
>>> d["k"] = Integer(4)
>>> d.dot("k")
4

external_string()[source]¶

EXAMPLES:

Sage

sage: R = macaulay2("QQ[symbol x, symbol y]")
sage: R.external_string()
'QQ[x..y, Degrees => {2:1}, Heft => {1}]'

Python

>>> from sage.all import *
>>> R = macaulay2("QQ[symbol x, symbol y]")
>>> R.external_string()
'QQ[x..y, Degrees => {2:1}, Heft => {1}]'

name(new_name=None)[source]¶

Get or change the name of this Macaulay2 element.

INPUT:

new_name – string (default: None); if None, return the name of this element. Else return a new object identical to self whose name is new_name.

Note that this can overwrite existing variables in the system.

EXAMPLES:

Sage

sage: S = macaulay2(QQ['x,y'])
sage: S.name()
'sage...'
sage: R = S.name("R")
sage: R.name()
'R'
sage: R.vars().cokernel().resolution()
 1      2      1
R  <-- R  <-- R  <-- 0

0      1      2      3

Python

>>> from sage.all import *
>>> S = macaulay2(QQ['x,y'])
>>> S.name()
'sage...'
>>> R = S.name("R")
>>> R.name()
'R'
>>> R.vars().cokernel().resolution()
 1      2      1
R  <-- R  <-- R  <-- 0
<BLANKLINE>
0      1      2      3

The name can also be given at definition:

Sage

sage: A = macaulay2(ZZ['x,y,z'], name='A')
sage: A.name()
'A'
sage: A^1
 1
A

Python

>>> from sage.all import *
>>> A = macaulay2(ZZ['x,y,z'], name='A')
>>> A.name()
'A'
>>> A**Integer(1)
 1
A

sage_polystring()[source]¶

If this Macaulay2 element is a polynomial, return a string representation of this polynomial that is suitable for evaluation in Python. Thus * is used for multiplication and ** for exponentiation. This function is primarily used internally.

EXAMPLES:

Sage

sage: R = macaulay2.ring('QQ','(x,y)')
sage: f = macaulay2('x^3 + 3*y^11 + 5')
sage: print(f)
 3     11
x  + 3y   + 5
sage: f.sage_polystring()
'x**3+3*y**11+5'

Python

>>> from sage.all import *
>>> R = macaulay2.ring('QQ','(x,y)')
>>> f = macaulay2('x^3 + 3*y^11 + 5')
>>> print(f)
 3     11
x  + 3y   + 5
>>> f.sage_polystring()
'x**3+3*y**11+5'

sharp(x)[source]¶

EXAMPLES:

Sage

sage: a = macaulay2([1,2,3])
sage: a.sharp(0)
1

Python

>>> from sage.all import *
>>> a = macaulay2([Integer(1),Integer(2),Integer(3)])
>>> a.sharp(Integer(0))
1

starstar(x)[source]¶

The binary operator ** in Macaulay2 is usually used for tensor or Cartesian power.

EXAMPLES:

Sage

sage: a = macaulay2([1,2]).set()
sage: a.starstar(a)
set {(1, 1), (1, 2), (2, 1), (2, 2)}

Python

>>> from sage.all import *
>>> a = macaulay2([Integer(1),Integer(2)]).set()
>>> a.starstar(a)
set {(1, 1), (1, 2), (2, 1), (2, 2)}

subs(*args, **kwds)[source]¶

Note that we have to override the substitute method so that we get the default one from Macaulay2 instead of the one provided by Element.

EXAMPLES:

Sage

sage: R = macaulay2("QQ[x]")
sage: P = macaulay2("ZZ/7[symbol x]")
sage: x, = R.gens()
sage: a = x^2 + 1
sage: a = a.substitute(P)
sage: a.sage().parent()
Univariate Polynomial Ring in x over Finite Field of size 7

Python

>>> from sage.all import *
>>> R = macaulay2("QQ[x]")
>>> P = macaulay2("ZZ/7[symbol x]")
>>> x, = R.gens()
>>> a = x**Integer(2) + Integer(1)
>>> a = a.substitute(P)
>>> a.sage().parent()
Univariate Polynomial Ring in x over Finite Field of size 7

underscore(x)[source]¶

EXAMPLES:

Sage

sage: a = macaulay2([1,2,3])
sage: a.underscore(0)
1

Python

>>> from sage.all import *
>>> a = macaulay2([Integer(1),Integer(2),Integer(3)])
>>> a.underscore(Integer(0))
1

class sage.interfaces.macaulay2.Macaulay2Function(parent, name)[source]¶: Bases: ExpectFunction

class sage.interfaces.macaulay2.Macaulay2FunctionElement(obj, name)[source]¶: Bases: FunctionElement

sage.interfaces.macaulay2.macaulay2_console()[source]¶

Spawn a new M2 command-line session.

EXAMPLES:

Sage

sage: macaulay2_console()                    # not tested
Macaulay 2, version 1.1
with packages: Classic, Core, Elimination, IntegralClosure, LLLBases, Parsing, PrimaryDecomposition, SchurRings, TangentCone
...

Python

>>> from sage.all import *
>>> macaulay2_console()                    # not tested
Macaulay 2, version 1.1
with packages: Classic, Core, Elimination, IntegralClosure, LLLBases, Parsing, PrimaryDecomposition, SchurRings, TangentCone
...

sage.interfaces.macaulay2.reduce_load_macaulay2()[source]¶

Used for reconstructing a copy of the Macaulay2 interpreter from a pickle.

EXAMPLES:

Sage

sage: from sage.interfaces.macaulay2 import reduce_load_macaulay2
sage: reduce_load_macaulay2()
Macaulay2

Python

>>> from sage.all import *
>>> from sage.interfaces.macaulay2 import reduce_load_macaulay2
>>> reduce_load_macaulay2()
Macaulay2

sage.interfaces.macaulay2.remove_output_labels(s)[source]¶

Remove output labels of Macaulay2 from a string.

s: output of Macaulay2
s: string

Returns: the input string with \(n\) symbols removed from the beginning of each line, where \(n\) is the minimal number of spaces or symbols of Macaulay2 output labels (looking like ‘o39 = ‘) present on every non-empty line.

Return type: string

Note

If s consists of several outputs and their labels have different width, it is possible that some strings will have leading spaces (or maybe even pieces of output labels). However, this function will try not cut any messages.

EXAMPLES:

Sage

sage: from sage.interfaces.macaulay2 import remove_output_labels
sage: output = 'o1 = QQ [x, y]\n\no1 : PolynomialRing\n'
sage: remove_output_labels(output)
'QQ [x, y]\n\nPolynomialRing\n'

Python

>>> from sage.all import *
>>> from sage.interfaces.macaulay2 import remove_output_labels
>>> output = 'o1 = QQ [x, y]\n\no1 : PolynomialRing\n'
>>> remove_output_labels(output)
'QQ [x, y]\n\nPolynomialRing\n'