[R] - detecting outliers

[Ben Bolker]

Joachim Audenaert <Joachim.Audenaert <at> pcsierteelt.be> writes:

> 
> Hello all,
> 
> I am estimating parameters for regression functions on experimental data. 
> Functional response of Rogers type II.
> 
> I would like to know which points of my dataset are outliers. What is the 
> best method to do this with R?

  The best method for detecting outliers really depends on the
motivation/purpose.  Your data look noisy, but by eye nothing
really jumps out.  Looking at a histogram (hist()) and Q-Q plot
qqnorm() of the residuals of the fit, it looks like the distribution
is slightly skewed but that there are no points that really fall
very far outside a normal distribution (normality is not a necessity
for making inferences from an nls fit, but it helps a lot)