# sample_spc: Incremental Samples from a Frequency Spectrum (zipfR) In zipfR: Statistical Models for Word Frequency Distributions

## Description

Compute incremental random samples from a frequency spectrum (an object of class `spc`).

## Usage

 `1` ``` sample.spc(obj, N, force.list=FALSE) ```

## Arguments

 `obj` an object of class `spc`, representing a frequency spectrum `N` a vector of non-negative integers in increasing order, the sample sizes for which incremental samples will be generated `force.list` if `TRUE`, the return value will always be a list of `spc` objects, even if `N` is just a single integer

## Details

This function is currently implemented as a wrapper around `sample.tfl`, using `spc2tfl` and `tfl2spc` to convert between frequency spectra and type frequency lists. A direct implementation might be slightly more efficient, but would very likely not make a substantial difference.

## Value

If `N` is a single integer (and the `force.list` flag is not set), a `spc` object representing the frequency spectrum of a random sample of size N from `obj`.

If `N` is a vector of length greater one, or if `force.list=TRUE`, a list of `spc` objects representing the frequency spectra of incremental random samples of the specified sizes N. Incremental means that each sample is a superset of the preceding sample.

## See Also

`spc` for more information about frequency spectra

`sample.tfl` is an analogous function for type frequency lists (objects of class `tfl`)

`sample.spc` takes a single concrete random subsample from a spectrum and returns the spectrum of the subsample, unlike `spc.interp`, that computes the expected frequency spectrum for random subsamples of size `N` by binomial interpolation.

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11``` ```## read Brown spectrum data(Brown.spc) summary(Brown.spc) ## sample a spectrum of 100k tokens MiniBrown.spc <- sample.spc(Brown.spc,1e+5) summary(MiniBrown.spc) ## if we repat, we get a different sample MiniBrown.spc <- sample.spc(Brown.spc,1e+5) summary(MiniBrown.spc) ```

zipfR documentation built on Aug. 17, 2017, 5:05 p.m.