Plots observed R^2 vs expected R2 under null of 0 correlation

qqR2.R

qqR2 <- function(corvec,nn,pad_neg_with_0 = FALSE,...)
{
## nn is the sample size, number of individuals used to compute correlation.
## needs correlation vector as input.
## nullcorvec generates a random sample from correlation distributions, under the null hypothesis of 0 correlation using Fisher's approximation.
  if(pad_neg_with_0) corvec[corvec < 0 | is.na(corvec) ]=0
  mm <- length(corvec)
  nullcorvec = tanh(rnorm(mm)/sqrt(nn-3)) ## null correlation vector
  qqplot(nullcorvec^2,corvec^2,...); abline(0,1); grid()
}

qqR <- function(corvec,nn,...)
{
## nn is the sample size, number of individuals used to compute correlation.
## needs correlation vector as input.
## nullcorvec generates a random sample from correlation distributions, under the null hypothesis of 0 correlation using Fisher's approximation.
  mm <- length(corvec)
  nullcorvec = tanh(rnorm(mm)/sqrt(nn-3)) ## null correlation vector
  qqplot(nullcorvec,corvec,...); abline(0,1); grid()
}