Scaling arguments: pc.biplot, obs.scale, var.scale

[hphillips97]

Variable arrows - pc.biplot

The documentation states that when argument pc.biplot = TRUE, this should scale the observations up by sqrt(n) and scale the variables scaled down by sqrt(n). However, looking at the source, only the observations are scaled, but not the variables:

if (pc.biplot) {
    df.u <- df.u * nobs.factor
}

If this is to be inline with the documentation, I believe this should be:

if (pc.biplot) {
    df.u <- df.u * nobs.factor
    df.v <- df.v / nobs.factor
}

However, I can see that df.v later gets scaled in a completely different way, regardless of whether pc.biplot = TRUE. Perhaps I'm missing something.

Scale - obs.scale and var.scale

The documentation also states the scale factor α allows the variances of the components to be apportioned between the row
points and column vectors by representing the approximation X as X = (U Λ^α) (Λ^(1−α) V^T).

The default value for the scale argument is 1 as expected. However, the default value for obs.scale = 1 - scale and var.scale = scale.

It looks like the two default values for obs.scale and var.scale should be swapped? At least that's how I would interpret it from the documentation.