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help for ^fpgraph^           (STB-21: sg26, STB-22: sg26.1, STB-25: sg26.3)
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Graph fractional polynomial model
---------------------------------

	^fpgraph^ [^,^ ^dr^esid^(^dresvar^)^ ^et^a^(^etavar^)^ ^nopt^s ^nogr^aph graph_options ]


Description
-----------

^fpgraph^ plots the data and fit from the most recently fitted fractional
polynomial (FP) model.  More precisely, it produces a component-plus-residual
plot.  For constant-weight, normal-error models with a single covariate,
this amounts to a plot of the observations with the fitted line inscribed.

For other normal-error models, (weighted) residuals are calculated in the
usual way.

For models with other covariates (specified in ^fp^ by ^base()^), the 
line is the partial linear predictor, obtained from the FP part of the
model only.  The values are adjusted so that their mean is the same as the
mean of the fit from the entire model.

For models with non-normal errors (e.g. logistic and Poisson regression),
`deviance residuals' are calculated.  These are added to the (partial)
linear predictor to give the `component+residual' values, which are plotted
as small circles.  Deviance residuals are more normally distributed than
alternatives such as Pearson residuals, so may make the plot more informative.
 

Limitations
-----------

^fpgraph^ is work in progress and does not handle all the possible models that
^fp^ itself can.  In particular, ^mlogit^ produces a prediction equation for
each level of the outcome variable and is not supported by ^fpgraph^.  The
^offset()^ and ^exposure()^ offset variables which are options of the ^poisson^
command are not currently allowed for.


Options
-------

^eta()^ saves the fitted component into a new variable, etavar.

^dresid()^ saves the deviance residuals into a new variable, dresidvar.

^nopts^ prevents the partial residuals being plotted; only the fitted component
    is displayed.

^nograph^ suppresses the graph.

graph_options are any of the standard Stata ^graph^ options.


Also see
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    STB:  STB-21: sg26,  STB-22: sg26.1,  STB-25: sg26.3
On-line:  help for @fp@.