A random race with given BT strengths

Returns a rank vector suitable for interpretation with race().

rrace(strengths)

Arguments

strengths

Named vector with names being players and values being their Bradley-Terry strengths

Details

Uses a simple recursive system to generate the ranks.

Value

Returns a character vector with entries corresponding to the competitor. The first element is the winner, the second the runner-up, and so on, until the final element is the last to cross the finishing line.

Author

Robin K. S. Hankin

See also

rrace3,hyper2

Examples

o <- c(a=0.4, b=0.3, c=0.2, d=0.1)
rrace(o)
#> [1] "b" "d" "a" "c"

suppfun(rrace(o))
#> log( a * (a + b + c + d)^-1 * b * (b + c + d)^-1 * c * (c + d)^-1)

table(replicate(100,rrace(o)[1]))  # should be about 40% "a"
#> 
#>  a  b  c  d 
#> 36 33 22  9 

as.ranktable(t(replicate(10, rrace(o)))) # same as rrank(10,o)
#> A ranktable:
#>       c1 c2 c3 c4
#>  [1,] c  d  b  a 
#>  [2,] b  c  a  d 
#>  [3,] b  a  c  d 
#>  [4,] d  a  b  c 
#>  [5,] a  d  b  c 
#>  [6,] a  c  d  b 
#>  [7,] a  c  b  d 
#>  [8,] d  b  a  c 
#>  [9,] a  d  b  c 
#> [10,] d  a  b  c