simslapmeg {SlaPMEG}

Simulate longitudinal data based on a shared latent process mixed effects model (SlaPMEG)

Description

This is a simple function to simulate longitudinal data from a shared latent process mixed effects model the data provides a good example for application of slapmeg and pairslapmeg and pairslapmeg objects.

Usage

simslapmeg(
  nY,
  ntime,
  nsubj,
  pDif = 1/3,
  fixed = ~1 + time,
  random = ~1 + time,
  fixedbeta = c(0, 2),
  randbeta = c(0, 2),
  group,
  groupbeta = 2,
  sigma.b,
  sigma.u,
  seed = as.integer(runif(1, 0, .Machine$integer.max)),
  returnpar = FALSE
)

Arguments

nY

number of omics in the data

ntime

number of repeated measures

nsubj

number of subjects

pDif

proportion of differentially expressed omics in the data (the default is 1/3)

fixed

A one-sided formula for the fixed-effects excluding the group variable, the default includes an intercept and time

random

A one-sided formula for the random-effects, the default includes an intercept and time

fixedbeta

effect size of fixed terms in formula, the length should match the fixed formula, the default is 0 (intercept) and 2 (time)

randbeta

effect size of random terms in formula, the length should match the random formula, the default is 0 (intercept) and 2 (time)

group

Vector indicating group membership, the length should match the number of subjects, The default is random allocation of half of subjects to each group. If use with slapmeg is intended, the group variable should have only two groups

groupbeta

effect size of group variable, the default is 2

sigma.b

variance of the omic- / subject- specific random effects, the length should math nY. If not specified, nY values from normal distribution will be randomly assigned.

sigma.u

Variance of the subject-specific random effects, the length should math the random effects defined in random formula. If not specified, 2 values from normal distribution will be randomly assigned.

seed

Value of seed, if not specified a random integer will be assigned

returnpar

logical if TRUE, all simulation parameters will be returned along with the simulated data.

Value

Returns a dataframe where the rows represent the observations and the columns represent the subject Id, time and group variable followed by the omics in pathway; if returnpar is TRUE, a list with both data and parametrs is returned

Author(s)

Mitra Ebrahimpoor

See Also

slapmeg, pairslapmeg