# Random Sampling of Plain Text in R

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If you are mining with a text source, performing some language modelling, you need to sample from a text corpus. I was wondering how to have a function to randomly selects chunks of a text file efficiently and is doing the job fast. I wanted to keep the function as simple as possible and using basic S3 methods in R.

###### Solution

I heavily encourage you to use `scan`

function that is a S3 basic R function:

sampleText <- function (filename, total, sampleSize) { lineNumber = sample(total, sampleSize) sample <- list() for (line in lineNumber) { result <- scan(filename, what="character", skip= line, nlines=1, sep="\n", strip.white = TRUE, fileEncoding = 'UTF-8') sample <- list(sample, result) } return(unlist(sample)) }

And here's how to use it:

sample <- createPartition('path_to_file.txt', 2000, 10)

Inspecting result:

> class(sample) [1] "character" > sample [1] "It's a cloudy day" [2] "But I did want her to have at least PART of my imaginary Paris experience, so I used her pretty Paris stamp to make her birthday card." ... [10] "Our smartest friend (Zachary)- was nice enough to study the injection and give us some information to share with everyone..."

**NOTE**: The reason that this function is fast is that you send in a file connection. If you are working with different encoding, to change values accordingly. Also, make sure that in case you want sentences back, set `sep='.'`

.

Hope you find this function useful! ?

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