SED navigation bar go to SED home page go to Dataplot home page go to NIST home page SED Home Page SED Staff SED Projects SED Products and Publications Search SED Pages

Dataplot Vol 1 Vol 2


RF SPREAD PLOT

Name:
    RF SPREAD PLOT
Type:
    Graphics Command
Purpose:
    Generates a residuals-fitted (r-f) spread plot.
Description:
    The residuals-fitted (r-f) spread plot is a graphical measure of the goodness of fit. That is, this command is preceeded by some type of fit. It plots percent point (or quantile) plots of the fitted values minus their mean and the residuals arranged side by side with a common vertical scale.

    The vertical spread of the residuals compared to the vertical spread of the fitted values gives an indication of how much of the variation is explained by the fit.

    Dataplot assumes that some type of fit has already been performed and that the predicted values are stored in the internal variable PRED and the residuals are stored in the internal variable RES. If you want to generate the rf spread plot for variables that are not automatically stored on PRED and RES, then simply copy the desired variables into PRED and RES before entering the RF SPREAD PLOT (e.g., LET PRED = Y).

Syntax:
    RF SPREAD PLOT <SUBSET/EXCEPT/FOR qualification>
    where the <SUBSET/EXCEPT/FOR qualification> is optional.
Examples:
    FIT Y X
    RF SPREAD PLOT

    LOWESS Y X
    RF SPREAD PLOT

    SPLINE FIT Y X
    RF SPREAD PLOT

Default:
    None
Synonyms:
    None
Related Commands:
    LINES = Sets the type for plot lines.
    CHARACTER = Sets the type for plot characters.
    PERCENT POINT PLOT = Generates a percent point plot.
    PLOT = Generates a data or function plot.
Reference:
    Cleveland, William S. (1993), "Visualizing Data", Hobart Press,
Applications:
    Exploratory Data Analysis
Implementation Date:
    2000/1
Program:
    SKIP 25
    READ BERGER1.DAT Y X
    FIT Y X
    CHARACTER CIRCLE
    LINE BLANK
    RF SPREAD PLOT

    plot generated by sample program

Date created: 06/05/2001
Last updated: 12/04/2023

Please email comments on this WWW page to alan.heckert@nist.gov.