DHARMa (version 0.1.3)

plotSimulatedResiduals: DHARMa standard residual plots

Description

This function creates standard plots for the simulated residuals

Usage

plotSimulatedResiduals(simulationOutput, quantreg = T)

Arguments

simulationOutput

an object with simualted residuals created by simulateResiduals

quantreg

whether to perform a quantile regression on 0.25, 0.5, 0.75. If F, a spline will be created instead

Details

The function creates two plots. To the left, a qq-uniform plot to detect deviations from overall uniformity of the residuals, and to the right a plot of residuals against predicted values. For a correctly specified model we would expect

a) a uniform (flat) distribution of the overall residuals, evidenced by a straight line in the qq-plot

b) uniformity in y direction if we plot against any predictor, including the predicted value.

To provide a visual aid in detecting deviations from uniformity in y-direction, the plot of the residuals against the predited values also performs an (optional) quantile regression, which provides 0.25, 0.5 and 0.75 quantile lines across the plots. These lines should be straight, horizontal, and at y-values of 0.25, 0.5 and 0.75. Note, however, that some deviations from this are to be expected by chance, even for a perfect model, especially if the sample size is small.

The quantile regression can take some time to calculate, especially for larger datasets. For that reason, quantreg = F can be set to produce a smooth spline instead.

See Also

plotResiduals