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


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

This program estimates L_infinite and K parameters of the von Bertalanffy 
growth function using mean size (length) at age data according to the 
procedure proposed by Gulland and Holt (1959). This ado file draws the linear 
relationship used for the estimation and provides a table with the estimated 
L_infinite and K parameters of the von Bertalanffy growth function.


Options
-------


^nograph^ suppresses the graph drawing.

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


Remarks
-------

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


Examples
--------

	. ^gullholt mlength age^

Will display the Gulland-Holt plot, a table with regression info, the values 
for L_infinite and K parameters of the von Bertalanffy growth function.

	. ^gullholt mlength age, xlab ylab^

Nice numbers for the axis added.


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

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