fitGammaIntercept {limma} | R Documentation

## Fit Intercept to Vector of Gamma Distributed Variates

### Description

Fit Intercept to Vector of Gamma Distributed Variates

### Usage

    fitGammaIntercept(y,offset=0,maxit=1000)

### Arguments

`y` | numeric vector of positive response values.
`offset` | numeric vector giving known part of the expected value of `y`. Can be a single value, or else a vector of the same length as `y`.
`maxit` | maximum number of Newton iterations to be done.

### Details

The values `y` are assumed to follow a gamma distribution with common shape parameter and with expected values given by `x+offset`. The function implements a globally convergent Newton iteration to estimate `x`.

### Value

Numeric value giving intercept.

### Author(s)

Gordon Smyth and Belinda Phipson

### References

Phipson, B. (2013). Empirical Bayes modelling of expression profiles and their associations. PhD Thesis. University of Melbourne, Australia.

### See Also

This function is called by `genas`.

### Examples

    offset <- runif(10)
    x <- 9
    mu <- x+offset
    y <- rgamma(10,shape=20,scale=mu/20)
    fitGammaIntercept(y,offset=offset)

[Package limma version 3.38.3 Index]