Normal Probability Plot with Simulation Envelope

Produces a normal probability (QQ) plot of the randomized quantile residuals together with a simulated envelope, reproducing the residual diagnostic figure of the paper. Points falling outside the envelope indicate poor fit.

Usage

envelope_qq(X, t, nrep = 100)

Arguments

X

A numeric design matrix with an intercept column.

t

A numeric vector of strictly positive responses.

nrep

Number of simulated samples used to build the envelope (default 100).

Value

Invisibly, a list with components r (observed residuals), e1 and e2 (lower and upper envelope bounds), and med (envelope median). A base-graphics plot is produced as a side effect.

References

Atkinson, A. C. (1985). Plots, Transformations and Regression. Oxford University Press.

See also

rqrandomized.

Examples

data(itajai)
X <- cbind(1, itajai$pressure)
envelope_qq(X, itajai$wind, nrep = 100)