Regression - Diagnostic - Plot - Residuals vs Fitted extension

From Q
Jump to: navigation, search

A chart of residual versus fitted values from a regression model. See this Cross Validated post for a discussion of the interpretation of this diagnostic.

Example

An example output from running this QScript on a Regression - Linear Regressionlinear regression output is shown below.

Acknowledgements

Uses the plot.lm or plot.glm function from the stats R package.

References

Bock, T. (2018, August 3) What are Residuals? [Blog post]. Accessed from https://www.displayr.com/learn-what-are-residuals/.

Code

includeWeb("QScript R Output Functions");

var is_displayr = (!!Q.isOnTheWeb && Q.isOnTheWeb());
if (!is_displayr)
{
    if (Q.fileFormatVersion() >= 17.13)
        main();
    else
        alert("Please update Q to use this feature from the extension button, or run it from the menu via Create > Regression > Diagnostic > Plot > Residuals vs Fitted.");
}
else
{
    main();
}

function main() {

    // The following 2 variables contain information specific to this diagnostic.
    var required_class = "Regression";
    var output_name_suffix = "residuals.vs.fitted";
    
    var item = checkSelectedItemClass(required_class);
    if (item == null)
        return false;
    var r_name = stringToRName(item.referenceName);

    // The following lines contain the R code to run
    var expression = "plot(" + r_name + ", which = 1)"

    return createROutput(item, expression, output_name_suffix);
}