Class CSVFrequencySampler

java.lang.Object

io.nosqlbench.virtdata.library.basics.shared.distributions.CSVFrequencySampler

All Implemented Interfaces:

LongFunction<String>

public class CSVFrequencySampler
extends Object
implements LongFunction<String>

Takes a CSV with sample data and generates random values based on the relative frequencies of the values in the file. The CSV file must have headers which can be used to find the named columns. I.E. take the following imaginary `animals.csv` file: animal,count,country puppy,1,usa puppy,2,colombia puppy,3,senegal kitten,2,colombia `CSVFrequencySampler('animals.csv', animal)` will return `puppy` or `kitten` randomly. `puppy` will be 3x more frequent than `kitten`. `CSVFrequencySampler('animals.csv', country)` will return `usa`, `colombia`, or `senegal` randomly. `colombia` will be 2x more frequent than `usa` or `senegal`. Use this function to infer frequencies of categorical values from CSVs.

Constructor Summary

Constructors

Constructor	Description
CSVFrequencySampler(String filename, String columnName)	Create a sampler of strings from the given CSV file.

Method Summary

Modifier and Type	Method	Description
String	apply(long value)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

CSVFrequencySampler

public CSVFrequencySampler(String filename,
 String columnName)

Create a sampler of strings from the given CSV file. The CSV file must have plain CSV headers as its first line.

Parameters:

filename - The name of the file to be read into the sampler buffer

columnName - The name of the column to be sampled

Method Details

apply

public String apply(long value)

Specified by:

apply in interface LongFunction<String>