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help for ^gullplot^                                               [STB-53: sg128]
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Gulland method for von Bertalanffy growth function parameter estimation
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     ^gullplot^  msizevar [^if^ exp] [^in^ range]
               [ ^,^ ^nog^raph graph_options]


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

This program estimates L_inf and K parameters of the von Bertalanffy growth 
function using mean at age data according to the procedure proposed by 
Chapman (1961) and later by Gulland (1969). This ado file draws 
the (l_t) vs. (l_t+1 - l_t) graph and provides a table with the numerical 
results.


Options
-------

^nograph^ suppresses the graph drawing

graph_options are any of the options allowed with ^graph, twoway^.


Remarks
-------

If the l_t-delta_t points do not have a slope less than zero, the program
halts and exits with an error message.


Examples
--------

	. ^gullplot mlength^

Will display the Gulland plot, a table with regression info and the
estimations for L_inf and K parameters of the von Bertalanffy equation.

	. ^gullplot mlength, xlab ylab^

Nice numbers for the axis added.

	. ^gullplot mlength, xlab ylab nog^

Suppresses the graphical display leaving only the table with numerical 
results.


Author
------

Isaias H. Salgado-Ugarte
Universidad Nacional Autonoma de Mexico
Facultad de Estudios Superiores Zaragoza
Biologia, Guelatao 66 Col. Ejercito de Oriente
Iztapalapa 09230, Mexico D.F., Mexico
(Fax 52-5-773-0151)
e-mail: isalgado@@servidor.unam.mx


Also see
--------

    STB: snp6 (STB-16); sg23 (STB-18) snp6.1 (STB-26); snp6.2 (STB-27)
         snp13 (STB-38)

On-line: ^help^ for  @fordwal@, @bevholt@, @gullholt@, @nlvbgf@