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help for ^qgamma4^
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Quantile-quantile plot for data vs fitted gamma distribution
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    ^qgamma4^ varname [^if^ exp] [^in^ range]
    [ ^,^ ^a^lpha^(^#^)^  ^b^eta^(^#^)^ ^t^ransform ^gr^id graph_options ]

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

^qgamma4^ plots the quantiles of varname against the quantiles of a
two-parameter gamma distribution with shape parameter alpha and scale
parameter beta. By default, alpha and beta are taken from S_alpha and
S_beta, which is where ^gamma4^ puts maximum likelihood estimates of
them.

Note: this is the original version of ^qgamma^, written for Stata 4. 
Users of Stata 8 up should switch to ^qgamma^. 

Options
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^alpha(^#^)^ sets alpha to #.

^beta(^#^)^ sets beta to #.

^transform^ applies a cube-root transform to both data and fitted
    quantiles. This may be useful for highly skewed data. The result
    should be closer to a Gaussian (normal) distribution.

^grid^ adds grid lines at the .05, .10, .25, .50, .75, .90, and .95
    quantiles.

graph_options are any of the options allowed with ^graph, twoway^; see
    help for ^graph^.

Examples
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        . ^gamma4 precip^
        . ^qgamma4 precip^
        . ^qgamma4 precip, t^

Author
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         Nicholas J. Cox, University of Durham, U.K.
         n.j.cox@@durham.ac.uk

Also see
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On-line: help for @graph@, @gamma4@, @pgamma4@