nullGen: Mediate the generation of statistical null values for the...
In mcglinnlab/vario: Community variograms and associated null models

nullGen

R Documentation

Mediate the generation of statistical null values for the variograms

This function is to be used in a parrallel processing loop which will generate a population of null values

nullGen(
  pop,
  vobject,
  coords,
  meth,
  sp,
  all = FALSE,
  RPargs = FALSE,
  median = FALSE
)

`pop`	the species x row x col array where row and column refer to spatial location
`vobject`	the output of the vario function with serves as the basis for empirical comparisons
`coords`	the spatial coordinates of a M^2 x S matrix
`meth`	the type of permutation to use, options include: reflect: random reflection/rotations of species (only makes sence when sp are not fixed shift: random torodial shifting with or with sp fixed both: both reflection and shifting random: random shuffle randpat: random patterns algo of Roxburgh and Chesson 1998, must parameterize RPargs (See below)
`sp`	boolean, if FALSE then obs composition of quadrats is fixed to the observed pattern, if TRUE then species are each shuffled independently
`all`	boolean, if TRUE then all relevant nulls are calculated
`RPargs`	a list of arguments that must be supplied if the random patterns algo is desired, the arguments of RPargs are input into the function 'randPatPar', they include: 1) allRP if TRUE & all = TRUE, then Random Patterns algo used as the spatial null, 2)nstrata, 3)mtrials1, 4)mtrials2, 5)alpha, 6)npar
`median:`	if TRUE then means and medians are calculated Note: 'meth' and 'sp' are arguments to randomization function 'spatPerm2D'