This function runs a non-parametric phase model on 14C and non-14C ages via Gaussian Mixture density estimation through the mclust package

```
BchronDensityFast(
ages,
ageSds,
calCurves,
pathToCalCurves = system.file("data", package = "Bchron"),
dfs = rep(100, length(ages)),
samples = 2000,
G = 30
)
```

## Arguments

- ages
A vector of ages (most likely 14C)

- ageSds
A vector of 1-sigma values for the ages given above

- calCurves
A vector of values containing either `intcal20`

, `shcal20`

, `marine20`

, or `normal`

(older calibration curves such as intcal13 are also supported). Should be the same length the number of ages supplied. Non-standard calibration curves can be used provided they are supplied in the same format as those previously mentioned and are placed in the same directory. Normal indicates a normally-distributed (non-14C) age.

- pathToCalCurves
File path to where the calibration curves are located. Defaults to the system directory where the 3 standard calibration curves are stored.

- dfs
Degrees-of-freedom values for the t-distribution associated with the calibration calculation. A large value indicates Gaussian distributions assumed for the 14C ages

- samples
Number of samples of calibrated dates required

- G
Number of Gaussian mixture components

## Value

An object of class `BchronDensityRunFast`

with the following components:

- out
The output from the run of `densityMclust`

with the given number of mixture components

- calAges
The calibrated ages from the `BchronDensity`

function

## Details

This is a faster approximate version of `BchronDensity`

that uses the `densityMclust`

function to compute the Gaussian mixtures for a set of calibrated ages. The method is an approximation as it does not fit a fully Bayesian model as `BchronDensity`

does. It is designed to be a probabilistic version of the Oxcal SUM command which takes calibrated ages and sums the probability distributions with the aim of estimating activity through age as a proxy.

## Examples

```
# \donttest{
# Read in some data from Sluggan Moss
data(Sluggan)
# Run the model
SlugDensFast <- with(
Sluggan,
BchronDensityFast(
ages = ages,
ageSds = ageSds,
calCurves = calCurves
)
)
# plot it
plot(SlugDensFast)
# }
```