The Subbotin distribution is given by the function:
$$ f(x;a,b,m) = \frac{1}{A} e^{- \frac{1}{b} \left|\frac{x-m}{a}\right|^b} $$
where \(m\) is a location parameter, \(b\) is a shape parameter, \(a\)
is a scale parameter and \(\Gamma\) represents the gamma function.
Since the Subbotin distribution is basically the exponential distribution
with scale parameter \(a = ab^{1/b}\) and \(m=0\), we use the same
method of the exponential power RNG and add the location parameter.
Details can be found on the documentation of the rpower function.