## Bactrian random walk operator

A random walk operator that selects a random dimension of the real parameter and perturbs the value a random amount according to a Bactrian distribution (Yang & Rodriguez, 2013), which is a mixture of two Gaussians:p(x) = 1/2*N(x;-m,1-m^2) + 1/2*N(x;+m,1-m^2) and more efficient than non-Bactrian RealRandomWalkOperator

`parameter`

(RealParameter)

The parameter to operate a random walk on. (required)

`scaleFactor`

(Double)

Scaling factor: larger means more bold proposals.
When `optimise`

is true, this is automatically tuned during MCMC (recommended).

`optimise`

(Boolean)

Flag to indicate that the scale factor is automatically changed in order to achieve a good acceptance rate (default true)

`kernelDistribution`

(KernelDistribution)

Provides sample distribution for proposals (optional, default: bactrian) See also kernel distributions.

`weight`

(Double)

Weight with which this operator is selected (required). See also operator weight tuning.

## References

Yang Z, Rodríguez CE. Searching for efficient Markov chain Monte Carlo proposal kernels. Proceedings of the National Academy of Sciences. 2013 Nov 26;110(48):19307-12. doi: 10.1073/pnas.1311790110.