GenBetaPrime

[azev77]

p. 124 it says:
Dagum(gamma, beta) = GenBetaPrime(a,s,1,gamma,-beta)
But Dagum only depends on two parameters (gamma,beta), not also on (a,s).

LogLogistic(a,s,beta) = GenBetaPrime(0,s,1,1,beta)
But LogLogistic only depends on 3 parameters (a,s,beta), but GenBetaPrime is missing a.

Also, the Kumaraswamy distribution is usually defined to be a two parameter family of distributions. But on p117 it depends on (a,s,gamma,beta)

[Gavin Crooks]

My general policy is to include location and scale parameters unless there is a compelling reason not to (e.g. chi-square).

So should be
Dagum(x; a,s gamma, beta) = GenBetaPrime(x;a,s,1,gamma,-beta),
and
LogLogistic(a,s,beta) = GenBetaPrime(a,s,1,1,beta)

Kumaraswamy is as intended.

Table 18.1 needs updating too.

[Gavin Crooks]

Fixed