SSgauss {xcms} | R Documentation

## Gaussian Model

### Description

This `selfStart` model evalueates the Gaussian model and its gradient. It has an `initial` attribute that will evalueate the inital estimates of the parameters `mu`, `sigma`, and `h`.

### Usage

    SSgauss(x, mu, sigma, h)

### Arguments

`x` | a numeric vector of values at which to evaluate the model
`mu` | mean of the distribution function
`sigma` | standard deviation of the distribution fuction
`h` | height of the distribution function

### Details

Initial values for `mu` and `h` are chosen from the maximal value of `x`. The initial value for `sigma` is determined from the area under `x` divided by `h*sqrt(2*pi)`.

### Value

A numeric vector of the same length as `x`. It is the value of the expression `h*exp(-(x-mu)^2/(2*sigma^2)`, which is a modified gaussian function where the maximum height is treated as a separate parameter not dependent on `sigma`. If arguments `mu`, `sigma`, and `h` are names of objects, the gradient matrix with respect to these names is attached as an attribute named `gradient`.

### Author(s)

Colin A. Smith, csmith@scripps.edu

### See Also

`nls`, `selfStart`

[Package xcms version 3.2.0 Index]