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Macaulay2Doc :: help

help -- help command

Description

Various ways to get help:
  • help "Macaulay2" -- displays the base of the online documentation tree.
  • help X -- displays the online documentation for X
  • help methods X -- displays help messages about the methods usable with things of type X
  • help methods res -- displays help messages about the methods usable with the function res
  • help methods symbol ** -- displays help messages about the methods usable with the operator **
  • help methods (res, X) -- displays help messages about the methods usable with the function res and a thing of class X
  • help methods (symbol **, X) -- displays help messages about the methods usable with the operator ** and a thing of class X
  • help methods (X, Y) -- displays help messages about the methods usable with a thing of class X and a thing of class Y
  • help about X -- displays documentation nodes from all installed packages whose keys contain X.
  • help about(X,Body=>true) -- displays documentation nodes from all installed packages whose keys or contents contain X.
The help command is used to display online documentation. Use viewHelp to display the corresponding documentation in your web browser.
i1 : help

o1 = initial help
     ************

     Welcome to Macaulay2


     Try entering '2+2' at your next input prompt, which begins with i.  The
     two output prompts begin with o.  The first one, with the equal sign,
     '=', gives the value computed from your input, and the second one, with
     the colon, ':', tells what type of thing the value is.


     Type one of these commands to get started reading the documentation:
       * copyright                         -- the copyright
       * help "Macaulay2"                  -- top node of the documentation.
       * help "reading the documentation"  -- 
       * help "getting started"            -- 
       * help "a first Macaulay2 session"  -- 
       * help x                            -- show documentation for x
       * help about x                      -- show documentation about x
       * help about (x,Body=>true)         -- show documentation mentioning x
       * ? f                               -- display brief documentation for
         a function f
       * printWidth = 80                   -- set print width to 80
         characters
       * viewHelp                          -- view documentation in a browser
       * viewHelp x                        -- view documentation on x in
         browser
     To read the documentation in info form, in case you happen to be running
     Macaulay2 in a terminal window, replace "help" by "infoHelp" in any of
     the commands above.

o1 : DIV
i2 : help ideal

o2 = ideal -- make an ideal
     **********************



     Ways to use ideal :
     ===================

       * "ideal(List)" -- make an ideal
       * ideal(Sequence), see "ideal(List)" -- make an ideal
       * "ideal(Matrix)" -- make an ideal
       * "ideal(Module)" -- converts a module to an ideal
       * "ideal(MonomialIdeal)" -- converts a monomial ideal to an ideal
       * ideal(QuotientRing), see "ideal(Ring)" -- returns the defining ideal
       * "ideal(Ring)" -- returns the defining ideal
       * ideal(Number), see "ideal(RingElement)" -- make an ideal
       * "ideal(RingElement)" -- make an ideal
       * "ideal(String)" -- make an ideal using classic Macaulay syntax
       * "ideal(Variety)" -- returns the defining ideal

o2 : DIV
i3 : help (ideal,List)

o3 = ideal(List) -- make an ideal
     ****************************

     Synopsis
     ========

       * Usage: ideal L
       * Function: "ideal"
       * Inputs:
           * L, a list, or a sequence of ring elements
       * Outputs:
           * an ideal, which is generated by the list or sequence of ring
             elements

     Description
     ===========

     +--------------------------------------------+
     |i1 : R = ZZ/101[w,x,y,z];                   |
     +--------------------------------------------+
     |i2 : ideal{x^2-w*y, x*y-w*z, x*z-y^2}       |
     |                                            |
     |             2                      2       |
     |o2 = ideal (x  - w*y, x*y - w*z, - y  + x*z)|
     |                                            |
     |o2 : Ideal of R                             |
     +--------------------------------------------+
     |i3 : ideal(y^2-x*z,x^2*y-z^2,x^3-y*z)       |
     |                                            |
     |             2         2     2   3          |
     |o3 = ideal (y  - x*z, x y - z , x  - y*z)   |
     |                                            |
     |o3 : Ideal of R                             |
     +--------------------------------------------+
     |i4 : E = ZZ/2[x,y, SkewCommutative => true];|
     +--------------------------------------------+
     |i5 : ideal(x^2,x*y)                         |
     |                                            |
     |o5 = ideal (0, x*y)                         |
     |                                            |
     |o5 : Ideal of E                             |
     +--------------------------------------------+
     |i6 : W = QQ[x,dx, WeylAlgebra => {x => dx}];|
     +--------------------------------------------+
     |i7 : ideal(dx*x+x*dx)                       |
     |                                            |
     |o7 = ideal(2x*dx + 1)                       |
     |                                            |
     |o7 : Ideal of W                             |
     +--------------------------------------------+
     |i8 : I = ideal(12,18)                       |
     |                                            |
     |o8 = ideal (12, 18)                         |
     |                                            |
     |o8 : Ideal of ZZ                            |
     +--------------------------------------------+
     |i9 : mingens I                              |
     |                                            |
     |o9 = | 6 |                                  |
     |                                            |
     |              1        1                    |
     |o9 : Matrix ZZ  <--- ZZ                     |
     +--------------------------------------------+

     An empty list or sequence of generators will yield an ideal of "ZZ",
     which can be promoted to another ring, if desired.

     +-------------------+
     |i10 : ideal ()     |
     |                   |
     |o10 = ideal ()     |
     |                   |
     |o10 : Ideal of ZZ  |
     +-------------------+
     |i11 : promote(oo,R)|
     |                   |
     |o11 = ideal ()     |
     |                   |
     |o11 : Ideal of R   |
     +-------------------+

     See also
     ========

       * "Ideal" -- the class of all ideals
       * "PolynomialRing" -- the class of all ordered monoid rings

o3 : DIV
Some other potential help topics:
  • help "Gröbner bases"
  • help "multigraded polynomial rings"

See also

For the programmer

The object help is a command.