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Macaulay2Doc :: random(Type)

random(Type) -- random element of a type

Synopsis

Description

Synopsis

  • Usage:
    random T
  • Inputs:
    • T, a type
    • Height => ...
  • 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 = .892711841846915

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

o2 = .561989839294559156675600137706+.246860627033766156612420945879*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
           -2 => 1
           -2 => 1
           -2 => 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
           -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
           1 => 1
           1 => 1
           1 => 1
           1 => 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
           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

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

      36    35    32    29    26    24    21    20    17    16    11    10  
o4 = a   + a   + a   + a   + a   + a   + a   + a   + a   + a   + a   + a   +
     ------------------------------------------------------------------------
      9    7    5    2
     a  + 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)

       5     4      3 2     2 3       4     5
o6 = 3x  + 6x y + 9x y  + 3x y  + 4x*y  + 8y

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

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

See also