Residual case order plot
rcoplot(r,rint) displays an errorbar plot of the confidence intervals on the residuals from a regression. The residuals appear in the plot in case order. Inputs r and rint are outputs from the regress function.
The following plots residuals and prediction intervals from a regression of a linearly additive model to the data in moore.mat:
load moore X = [ones(size(moore,1),1) moore(:,1:5)]; y = moore(:,6); alpha = 0.05; [betahat,Ibeta,res,Ires,stats] = regress(y,X,alpha); rcoplot(res,Ires)
The interval around the first residual, shown in red, does not contain zero. This indicates that the residual is larger than expected in 95% of new observations, and suggests the data point is an outlier.