The perturbation of two compositional vectors v and y is given (up to
compositional equivalence) by the elementwise product v * y.
perturb(x, y, ...) # S3 method for matrix perturb(x, y, margin, norm = "close") # S3 method for otu_table perturb(x, y, norm = "close") # S3 method for phyloseq perturb(x, y, norm = "close") # S3 method for mc_bias_fit perturb(x, y)
| x | An abundance matrix or phyloseq object containing one |
|---|---|
| y | A numeric vector with which to perturb the observations in x |
| margin | Matrix margin that corresponds to observations (samples);
|
| norm | String specifying how to normalize the perturbed observations; see Details. |
Let w = v * y, where v is a row or column of x. The normalization
options specified by the norm argument are
"close" Return the compositional closure of w into the simplex,
w / sum(w)
"keep" Keep the same total abundance as the original vector by returning
w * sum(v) / sum(w)
"none" Return w without any normalization
If y is named, then the names must agree with the taxa names in x and
will be used to reorder y to match the taxa order in x.