help simuped2, simuped3
                                                                 (STB-58: dm82)

-------------------------------------------------------------------------------

Title

    simuped2 --   Simulate two-generation families

    simuped3 --   Simulate three-generation families


Syntax

        simuped2 #Age1 #Std1 #Age2 #Std2 [, options]

        simuped3 #Age1 #Std1 #Age2 #Std2 #Age3 #Std3 [, options]


    options                Description
    -------------------------------------------------------------------------
    Main
      reps(#)              specifies the number of families to be simulated
      saving(filename)     specifies the file name of the simulated data
      alle(#)              specifies the allele frequency of a biallelic
                             locus A
      sib(#)               spcifies the mean number of siblings in the second
                             generation

    For simuped3 only
      si3(#)               spcifies the mean number of siblings in the third
                             generation
    -------------------------------------------------------------------------


Description

    simuped2 and simuped3 are immediate commands to generate two- and
    three-generation family data, respectively.  The number of siblings in a
    family is determined by a Poisson distribution with a mean specified by
    sib(#) or si3(#), where the Poisson variate is generated using rndpoix.
    This program needs to be installed before running simuped2 or simuped3.
    The gender of a person is determined by a Bernoulli distribution with
    mean 0.5 and age is determined by a normal distribution with means #Age1,
    #Age2 and #Age3 for the first, second and third generation, respectively.
    The corresponding standard deviation is given by #Std1, #Std2 and #Std3
    for the three generations, respectively.

    Hardy-Weinberg equilibrium is assumed for the genotypic distribution of
    people in the first generation (Elandt-Johnson 1971).  The allele
    frequency of a biallelic locus A is specified by option alle(#), denoted
    as p.  The frequencies of genotypes AA, Aa and aa in the first generation
    are given by p^2, 2p(1-p) and (1-p)^2, respectively.  The genotype of a
    person in the second- and third-generation is generated according the
    Mendelian inheritance, that is, a person inherits the allele A from the
    father (or mother) with probability 0.5. The simulated family data are
    saved in a file specified by saving(filename), and the number of
    replications is specified by reps(#).


Options

        +------+
    ----+ Main +-------------------------------------------------------------

    reps(#) specifies the number of families to be simulated.  The default
        value is 100.

    saving(filename) specifies the file name of the simulated data.  The
        default file name is temp.dta.

    alle(#) specifies the allele frequency of a biallelic locus A.  The
        default value is 0.1.

    sib(#) spcifies the number of siblings in the second generation.  The
        default value is 3.

        +-------------------+
    ----+ For simuped3 only +------------------------------------------------

    si3(#) spcifies the number of siblings in the third generation.  The
        default value is 3.


Examples

    clear

    simuped2 70 10 40 10, reps(1000) sav(output) alle(0.05) sib(5)

    simuped3 80 10 50 10 20 10, reps(2000) alle(0.1) sib(4) si3(3.5)


Also see

    STB:  STB-58: dm82


References

    Cui J. Simulating two- and three-generation families. Stata Technical
        Bulletin 2000; 58: 2-5.

    Elandt-Johnson R. Probability models and statistical methods in genetics.
        New York: John Wiley & Sons, 1971.


Author

    James Cui, Department of Epidemiology and Preventive Medicine, Monash
    University.

    Email: james.cui@med.monash.edu.au


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phenotype  (if installed)      ssc install phenotype    (to install this comman
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buckley    (if installed)      ssc install buckley      (to install this comman
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qic        (if installed)      ssc install qic          (to install this comman
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