generateAbundanceDF: Generate gene expression table or otu abundance table with...
In Tong-Chen/YSX: For Yishengxin Training

Generate gene expression table or otu abundance table with given samle information for test.

generateAbundanceDF(
  type = "Gene",
  mean = 20,
  nGene = 15,
  nGrp = 2,
  nSample = 3
)

`type`	Generate gene expression or OTU abundance. Only affect rownames.
`mean`	Mean value of abundance given to `rnorm`.
`nGene`	Number of genes or OTUs.
`nGrp`	Number of sample groups.
`nSample`	Number of sample replications for each group.
`sd`	Standard deviations given to `rnorm`.