plotDiagnostics is a public method of the LinearModel class. The function is defined in LinearModel.m and recieves a LinearModel object as input. plotDiagnostics is not defined in other model classes such as LinearMixedModel objects. Determine the class of your model using class(mdl) to confirm if it's a LinearModel object. If not, you cannot use plotDiagnostics with the model.
If the LinearModel class has not been constructed, help('plotDiagnostics') will not find the function unless you specify the class name,
help plotDiagnostics
plotDiagnostics not found.
Use the Help browser search field to search the documentation, or
type "help help" for help command options, such as help for methods.
help LinearModel.plotDiagnostics
plotDiagnostics Plot diagnostics of fitted model
plotDiagnostics(LM,PLOTTYPE) plots diagnostics from LinearModel LM in
a plot of type PLOTTYPE. The default value of PLOTTYPE is 'leverage'.
Valid values for PLOTTYPE are:
'contour' residual vs. leverage with overlayed Cook's contours
'cookd' Cook's distance
'covratio' delete-1 ratio of determinant of covariance
'dfbetas' scaled delete-1 coefficient estimates
'dffits' scaled delete-1 fitted values
'leverage' leverage (diagonal of Hat matrix)
's2_i' delete-1 variance estimate
H = plotDiagnostics(...) returns handles to the lines in the plot.
The PLOTTYPE argument can be followed by parameter/value pairs to
specify additional properties of the primary line in the plot. For
example, plotDiagnostics(LM,'cookd','Marker','s') uses a square
marker.
The data cursor tool in the figure window will display the X and Y
values for any data point, along with the observation name or number.
It also displays the coefficient name for 'dfbetas'.
Example:
% Plot the leverage in a fitted regression model
load carsmall
d = dataset(MPG,Weight);
d.Year = ordinal(Model_Year);
lm = fitlm(d,'MPG ~ Year + Weight + Weight^2')
plotDiagnostics(lm,'leverage')
% Look at the data for the high-leverage points, and note that
% their Weight values are near the extremes
high = find(lm.Diagnostics.Leverage>0.11)
d(high,:)
See also LinearModel, plotResiduals.
Documentation for LinearModel/plotDiagnostics
doc LinearModel.plotDiagnostics
The which function only works when the LinearModel class is constructed.
which plotDiagnostics
'plotDiagnostics' not found.
which plotDiagnostics
/MATLAB/toolbox/stats/classreg/@LinearModel/LinearModel.m % LinearModel method
