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help for ^qweibull4^
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Quantile-quantile plot for data vs fitted Weibull distribution
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    ^qweibull4^ varname [^if^ exp] [^in^ range]
    [ ^,^ ^b(^#^)^  ^c(^#^)^ ^gr^id graph_options ]

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

^qweibull4^ plots the quantiles of varname against the quantiles of a
two-parameter Weibull distribution with scale parameter b and shape
parameter c. By default, b and c are taken from S_2 and S_3, which is
where ^wbull^ puts maximum likelihood estimates of them.

The probability density function is

             c         c - 1               c
    f(x) =   -  (x / b)       exp(- (x / b) )
             b

for x >= 0, b > 0 and c > 0.

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

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

^c(^#^)^ sets c to #.

^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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        . ^wbull precip^
        . ^qweibull4 precip^

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@, @wbull@, @pweibull4@