README.md

In wrathematics/lineSampler: File Sampler

filesampler

• Version: 0.4-0
• Status:
• License: BSD 2-Clause
• Project home: https://github.com/wrathematics/lineSampler
• Bug reports: https://github.com/wrathematics/lineSampler/issues
• Author: Drew Schmidt

This is a simple R package to quickly read a random sample of lines of a flat text file (such as a csv) into R. This allows you to get a subsample into R without having to read the (possibly large) file into memory first.

If you would like to contribute to this project, please see the CONTRIBUTING.md file. Idea inspired by Eduardo Arino de la Rubia's fast_sample.

Installation

You can install the stable version from the HPCRAN using the usual install.packages():

install.packages("filesampler", repos="https://hpcran.org")

The development version is maintained on GitHub:

remotes::install_github("wrathematics/filesampler")

Package Use

library(filesampler)
ret <- sample_csv(file, p=.001)

There is also a sample_lines() function for reading in (line) subsamples of unstructured text akin to readLines(). See package vignette for more details.

For more information, including benchmarks and implementation details, please see the package vignette:

vignette("filesampler", package="filesampler")

Code Re-Use

The C code in the src/filesampler tree of this package can easily be re-purposed for use outside of R with some minor modifications. The components that need to be edited can be found in the file:

• src/filesampler/utils.h

Detailed explanations are contained there, but you will need:

• a uniform random number generator
• a print function (probably printf())
• an interrupt checker

wrathematics/lineSampler documentation built on Feb. 27, 2020, 8:01 p.m.