GenerateFrequencies {chickn} R Documentation

## Frequency vector construction

### Description

Function performs the data variance estimation and the frequency matrix construction.

### Usage

```GenerateFrequencies(Data, m, N0 = 5000, TypeDist = "AR", verbose = FALSE, ...)
```

### Arguments

 `Data` A Filebacked Big Matrix n x N with data vectors in columns. `m` Number of frequency vectors. `N0` Number of data vectors used for the variance estimation in `EstimSigma`. `TypeDist` Frequency distribution type. Possible values: "G" (Gaussian), "FG" (Folded Gaussian radial) or "AR" (Adapted radius). Default is "AR". `verbose` logical that indicates whether dysplay the process steps. `...` Additional arguments passed on to `EstimSigma` and `DrawFreq` functions.

### Details

The data variance is estimated on the `N0` data vectors randomly selected from `Data` using `EstimSigma` function. The frequency vectors are sampled using `DrawFreq` function.

### Value

A list with the following attributes:

• `W` is the frequency matrix with m frequency vectors in rows.

• `sigma` is the estimated data variance.

### References

Keriven N, Bourrier A, Gribonval R, Pérez P (2018). “Sketching for large-scale learning of mixture models.” Information and Inference: A Journal of the IMA, 7(3), 447–508..

### See Also

`DrawFreq`, `EstimSigma`, `Sketch`

### Examples

```X = matrix(rnorm(1000), ncol=100, nrow = 10)
X_FBM = bigstatsr::FBM(init = X, ncol=100, nrow = 10)
W = GenerateFrequencies(Data = X_FBM, m = 20, N0 = 100, TypeDist = "AR")\$W
```

[Package chickn version 1.2.3 Index]