AA.Aa.aa {VGAM} | R Documentation

## The AA-Aa-aa Blood Group System

### Description

Estimates the parameter of the AA-Aa-aa blood group system.

### Usage

    AA.Aa.aa(link = "logit", earg=list(), init.pA = NULL)

### Arguments

`link` | Link function applied to `pA`. See `Links` for more choices.
`earg` | List. Extra argument for the link. See `earg` in `Links` for general information.
`init.pA` | Optional initial value for `pA`.

### Details

This one parameter model involves a probability called `pA`. The probability of getting a count in the first column of the input (an AA) is `pA*pA`.

### Value

An object of class `"vglmff"` (see `vglmff-class`). The object is used by modelling functions such as `vglm` and `vgam`.

### Note

The input can be a 3-column matrix of counts, where the columns are AA, Ab and aa (in order). Alternatively, the input can be a 3-column matrix of proportions (so each row adds to 1) and the `weights` argument is used to specify the total number of counts for each row.

### Author(s)

T. W. Yee

### References

Weir, B. S. (1996) Genetic Data Analysis II: Methods for Discrete Population Genetic Data, Sunderland, MA: Sinauer Associates, Inc.

### See Also

`AB.Ab.aB.ab`, `AB.Ab.aB.ab2`, `ABO`, `G1G2G3`, `MNSs`.

### Examples

    y = cbind(53, 95, 38)
    fit = vglm(y ~ 1, AA.Aa.aa(link="logit"), trace=TRUE)
    fit = vglm(y ~ 1, AA.Aa.aa(link="probit"), trace=TRUE)
    rbind(y, sum(y)*fitted(fit))
    Coef(fit) # Estimated pA
    summary(fit)

[Package VGAM version 0.7-9 Index]