inst/doc/MarZIC.R

In MarZIC: Marginal Mediation Effects with Zero-Inflated Compositional Mediator

## ----include = FALSE----------------------------------------------------------
knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>"
)

library(MarZIC)

## -----------------------------------------------------------------------------
## A make up example with 1 taxon and 100 subjects.
set.seed(1)
nSub <- 200
nTaxa <- 10
## generate covariate of interest X
X <- rbinom(nSub, 1, 0.5)
## generate confounders
conf1<-rnorm(nSub)
conf2<-rbinom(nSub,1,0.5)

## generate mean of each taxon. All taxon are having the same mean for simplicity.
mu <- exp(-5 + X + 0.1 * conf1 + 0.1 * conf2) / 
  (1 + exp(-5 + X + 0.1 * conf1 + 0.1 * conf2))
phi <- 10

## generate true RA
M_taxon<-t(sapply(mu,function(x) dirmult::rdirichlet(n=1,rep(x*phi,nTaxa))))

P_zero <- exp(-3 + 0.3 * X + 0.1 * conf1 + 0.1 * conf2) / 
  (1 + exp(-3 + 0.3 * X + 0.1 * conf1 + 0.1 * conf2))

non_zero_ind <- t(sapply(P_zero,function(x) 1-rbinom(nTaxa,1,rep(x,nTaxa))))

True_RA<-t(apply(M_taxon*non_zero_ind,1,function(x) x/sum(x)))

## generate outcome Y based on true RA
Y <- 1 + 100 * True_RA[,1] + 5 * (True_RA[,1] > 0) + X + conf1 + conf2 + rnorm(nSub)

## library size was set to 10,000 for all subjects for simplicity.
libsize <- 10000

## generate observed RA
observed_AA <- floor(M_taxon*libsize*non_zero_ind)

observed_RA <- t(apply(observed_AA,1,function(x) x/sum(x)))
colnames(observed_RA)<-paste0("rawCount",seq_len(nTaxa))
CovData <- cbind(Y = Y, X = X, libsize = libsize, conf1 = conf1, conf2 = conf2)



## -----------------------------------------------------------------------------
## run the analysis
res <- MarZIC(
  MicrobData = observed_RA,
  CovData = CovData,
  lib_name = "libsize",
  y_name = "Y",
  x_name = "X",
  conf_name = c("conf1","conf2"),
  taxa_of_interest = c("rawCount1","rawCount2","rawCount3"),
  num_cores = 1,
  mediator_mix_range = 1
)



## -----------------------------------------------------------------------------
NIE1 <- res$NIE1_save

## -----------------------------------------------------------------------------
subset(NIE1, significance == TRUE)

## ----sessionInfo, echo=FALSE--------------------------------------------------
sessionInfo()