ggdmc (version 0.2.5.2)

PickChains: Draw n other chains and shuffle them

Description

This is part of DE-MCMC algorithm. PickChains draws n chains out of length(chains) chains, excluding the kth chain. GetSubchains is used in migration operator. It draws a subset of chains in nchain chains.

Usage

PickChains(k, nchain, chains)
GetSubchains(nchain)
SelectEmigrants(ngroup, k)

Arguments

k

the kth processed chain. Must be an integer within the range of 0 to nchain - 1. No check for errorly using R index.

nchain

number of chains to draw.

chains

an integer vector, indicating chain index, e.g., 0:23

ngroup

number of distributed groups

Value

a column vector

Details

Getsubchains is part of the Migration algroithms. It does two-step shuffling. In step 1, it selects a number l (integer) uniformly between 1 and k to be the number of subpopulations for migration. In step 2, it generates the chain index (0 to nchain - 1) and lastely it shuffles them

Examples

# NOT RUN {
chains <- 0:23

## Presuming current processing chain is the 1st chain (C index = 0)
## pick 2 chains out of 24 chains, excluding current chain.
PickChains(0, 2, chains)

## Example outputs
##      [,1]
## [1,]   17
## [2,]   12
##      [,1]
## [1,]    2
## [2,]    5
##      [,1]
## [1,]    5
## [2,]    3
##      [,1]
## [1,]   10
## [2,]    8
##      [,1]
## [1,]   15
## [2,]    8

## get a random number of subchains
GetSubchains(24)
##       [,1]
##  [1,]    0
##  [2,]    3
##  [3,]    5
##  [4,]    9
##  [5,]   10
##  [6,]   12
##  [7,]   14
##  [8,]   15
##  [9,]   18
## [10,]   20
## [11,]   21
## [12,]   22

# }