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help for ^bhataplt^                                               [STB-53: sg128]
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Bhattacharya's graph for Gaussian component determination     
---------------------------------------------------------

      ^bhataplt^ freqvar midpoivar [^if^ exp] [^in^ range]
                 [, ^g^en^(^logdivar^)^ ^nog^raph graph_options]
       

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

This program calculates from frequency and midpoint pair values, the 
logarithmic differences and draws the Bhathacharya's plot using the 
observation's numbers as plotting symbols in order to define negatively 
sloped lines, each one representing individual gaussian components in mixed 
distributions.

This routine is a new version integrating two previous simple programs:
diflogen.ado (logarithmic differences generator) and bhatplot.ado
(Bhattacharya's plot drawer).

Type ^help bhatado^ for information on
other ado-files used in applying Bhattacharya's method.


Options
-------

^gen(^logdif^)^ permits to create a variable with the logarithmic differences of 
            lagged frequencies. 

^nograph^ suppresses the graph drawing

^graph_options^ are any of the options allowed with ^graph, two^ except ^yline(#)^.


Remarks
-------

[^in^ range] can be used to limit the coverage of plotted points in order to
          clarify the graph and improve the point choice.

^symbol(^string^)^ is set to ^[_n]^ as an aid to select the points with negatively
          sloped points.


^yline(^#^)^ is used to draw a line indicating the zero difference and can not be 
          used for other value.


Examples
--------

  . ^bhataplt freq midpoi, gen(logdivar)^

Draws the Bhattacharya's plot and generates ^logdivar^ containing logarithmic
differences of lagged frequency values

  . ^bhataplt freq midpoi in 4/12^

Draws the Bhattacharya's plot for the limited range from _n=4 to _n=12


Reference
---------

   Salgado-Ugarte, I.H., J. Martinez-Ramirez, J.L. Gomez-Marquez, and B. 
        Pena-Mendoza. Some programs for fisheries biology. Growth estimation
        from length frequency analysis and hard parts reading. Stata 
        Technical Bulletin XX: XX-XX.


Author
------

Isaias H. Salgado-Ugarte
Facultad de Estudios Superiores 'Zaragoza',
Biology (Fax 52-5-773-1183)
E-mail: isalgado@@servidor.unam.mx

Also see
--------

    STB: sg23 (STB-18)
On-line: ^help^ for @bhattado@, @diflogen@, @bhatmesd@, @gaussgen@, @bhatgauc@