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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 = .509648647154435

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

o2 = .791973588544059560984538127737+.775803008900506178314457418342*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
           -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
           -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
           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
           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
           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
           4 => 1
           5 => 1
           5 => 1
           5 => 1
           5 => 1
           5 => 1
           5 => 1
           5 => 1

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

      39    35    34    31    30    28    24    23    22    15    14    8  
o4 = a   + a   + a   + a   + a   + a   + a   + a   + a   + a   + a   + a  +
     ------------------------------------------------------------------------
      7    4    2
     a  + a  + a  + 1

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)

       4      3 2     2 3       4     5
o6 = 3x y + 4x y  + 6x y  + 8x*y  + 7y

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

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

See also