next | previous | forward | backward | up | top | index | toc | Macaulay2 web site
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 = .282806250643787

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

o2 = .179872601236935424518667388645+.369238595528818593187061191039*ii

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

o3 = Tally{-1 => 3 }
           -2 => 13
           -3 => 14
           -4 => 12
           -5 => 8
           0 => 10
           1 => 9
           2 => 7
           3 => 10
           4 => 8
           5 => 7

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

      36    34    33    29    27    26    23    22    21    19    15    13  
o4 = a   + a   + a   + a   + a   + a   + a   + a   + a   + a   + a   + a   +
     ------------------------------------------------------------------------
      7    6    5    3
     a  + 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     3 2     2 3       4     5
o6 = 6x  + 6x y  + 8x y  + 5x*y  + 3y

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

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

See also