BEAST 2 Help Me Choose

# BEAST 2 Help Me Choose Bactrian up down operator

## Bactrian up down operator

Like the non Bactrian UpDownOperator, this element represents an operator that scales two (or more) parameters in different directions, but uses a Bactrian proposal distribution for the scale value. The up parameter is multiplied by this scale and the down parameter is divided by this scale.

## scaleFactor (Double)

Magnitude factor used for scaling. Larger values mean bolder proposals, but higher chance of rejection. When optimise is set to true, this value is automatically tuned during MCMC. A starting value of 0.1 seems to be OK in that case.

## up (StateNode)

Zero or more items to scale upwards (optional, default: [])

## down (StateNode)

Zero or more items to scale downwards (optional, default: [])

## optimise (Boolean)

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

## elementWise (Boolean)

Flag to indicate that the scaling is applied to a random index in multivariate parameters (default false) (optional, default: false)

## upper (Double)

Upper Limit of scale factor (optional, default: 10.0)

## lower (Double)

Lower limit of scale factor (optional, default: 0.0)

## 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.

## Bayesian evolutionary analysis by sampling trees

Disclaimer: The above is the opinion of the author RB. If you do not agree, or spot a mistake, contact the author, or discuss this in the issues area or raise a new issue. A link will be added from this page to make sure others can find it.

Served through Jekyll, customised theme based on the twentyfourteen wordpress theme.