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Macaulay2Doc :: random(Type)

random(Type) -- random element of a type

Synopsis

Description

Synopsis

  • Usage:
    random T
  • Inputs:
  • Outputs:
    • a random instance of the type T. If the Height option specifies a number h and T is ZZ and , then the integers returned are in the range 0 .. h-1; for QQ the numerator and denominator are in the range 1 .. h.
i1 : random RR

o1 = .783571055539501

o1 : RR (of precision 53)
i2 : random CC_100

o2 = .883069622694969064856248637201+.291862755303244838614942351637*ii

o2 : CC (of precision 100)
i3 : tally for i to 100 list random GF 11

o3 = Tally{-1 => 1}
           -1 => 1
           -1 => 1
           -1 => 1
           -1 => 1
           -1 => 1
           -1 => 1
           -1 => 1
           -1 => 1
           -2 => 1
           -2 => 1
           -2 => 1
           -2 => 1
           -2 => 1
           -2 => 1
           -3 => 1
           -3 => 1
           -3 => 1
           -3 => 1
           -3 => 1
           -3 => 1
           -3 => 1
           -3 => 1
           -3 => 1
           -3 => 1
           -4 => 1
           -4 => 1
           -4 => 1
           -4 => 1
           -4 => 1
           -4 => 1
           -4 => 1
           -4 => 1
           -4 => 1
           -4 => 1
           -4 => 1
           -5 => 1
           -5 => 1
           -5 => 1
           -5 => 1
           -5 => 1
           -5 => 1
           -5 => 1
           -5 => 1
           -5 => 1
           -5 => 1
           -5 => 1
           -5 => 1
           0 => 1
           0 => 1
           0 => 1
           0 => 1
           0 => 1
           0 => 1
           0 => 1
           0 => 1
           0 => 1
           0 => 1
           0 => 1
           1 => 1
           1 => 1
           1 => 1
           1 => 1
           1 => 1
           1 => 1
           1 => 1
           2 => 1
           2 => 1
           2 => 1
           2 => 1
           2 => 1
           2 => 1
           2 => 1
           2 => 1
           2 => 1
           3 => 1
           3 => 1
           3 => 1
           3 => 1
           3 => 1
           3 => 1
           3 => 1
           3 => 1
           3 => 1
           4 => 1
           4 => 1
           4 => 1
           4 => 1
           4 => 1
           4 => 1
           4 => 1
           5 => 1
           5 => 1
           5 => 1
           5 => 1
           5 => 1
           5 => 1
           5 => 1
           5 => 1
           5 => 1
           5 => 1

o3 : Tally
i4 : random GF(2,40)

      39    31    29    28    27    26    25    23    22    21    16    15  
o4 = a   + a   + a   + a   + a   + a   + a   + a   + a   + a   + a   + a   +
     ------------------------------------------------------------------------
      14    11    10    3
     a   + a   + a   + a

o4 : GF 1099511627776

Synopsis

  • Usage:
    random(d,R)
  • Inputs:
  • Outputs:
    • a random homogeneous element of the ring R of degree d
i5 : R = ZZ[x,y];
i6 : random(5,R)

       5     4      3 2     2 3     5
o6 = 6x  + 6x y + 4x y  + 9x y  + 6y

o6 : R
i7 : R = GF(25,Variable=>a)[x,y];
i8 : VerticalList for i to 6 list random(3,R)

     {           3             2              2             3    }
o8 = {(- 2a - 1)x  + (- a - 2)x y + (a + 2)x*y  + (- a - 2)y     }
     {           3             2                 2    3          }
     {(- 2a - 2)x  + (- a + 1)x y + (- 2a - 1)x*y  + y           }
     {   3      2              2           3                     }
     {a*x  + a*x y + (a - 1)x*y  + (a - 2)y                      }
     {      3            2        2     3                        }
     {- 2a*x  + (2a + 2)x y - 2x*y  + 2y                         }
     {          3           2        2           3               }
     {(- a - 1)x  + (a - 1)x y + 2x*y  + (a - 1)y                }
     {           3             2                 2              3}
     {(- 2a - 1)x  + (- a + 1)x y + (- 2a + 2)x*y  + (- 2a - 2)y }
     {           3      2                 2            3         }
     {(- 2a + 2)x  - a*x y + (- 2a + 2)x*y  + (2a + 2)y          }

o8 : VerticalList
The length of d, if it's a list, should be the same as degreeLength R.

See also