plot(mdl)
h = plot(mdl)
plot(
creates
a plot of the fitted linear model. The plot type depends on the number
of predictor variables.mdl
)
If there is just one predictor variable, plot
creates
a scatter plot of the data along with a fitted curve and confidence
bounds.
If there are multiple predictor variables, plot
creates
an added variable plot.
If there are no predictors, plot
creates
a histogram of the residuals.

Linear model, as constructed by 

Vector of handles to lines or patches in the plot. 
An added variable plot illustrates the incremental effect on the response of specified terms by removing the effects of all other terms. The slope of the fitted line is the coefficient of the linear combination of the specified terms projected onto the bestfitting direction. The adjusted response includes the constant (intercept) terms, and averages out all other terms.
Use plotAdded
to
select particular predictors for an added variable plot.