NGT PHP

NGT - high-speed approximate nearest neighbors - for PHP

Installation

Run:

composer require ankane/ngt

Add scripts to composer.json to download the shared library:

"scripts": {
"post-install-cmd": "Ngt\\Vendor::check",
"post-update-cmd": "Ngt\\Vendor::check"
}

And run:

composer install

On Mac, also install OpenMP:

brew install libomp

NGT is not available for Windows

Getting Started

Prep your data

$objects = [
[1, 1, 2, 1],
[5, 4, 6, 5],
[1, 2, 1, 2]
];

Create an index

$index = newNgt\Index($dimensions);

Insert objects

$index->batchInsert($objects);

Search the index

$index->search($query, size: 3);

Save the index

$index->save($path);

Load an index

$index = Ngt\Index::load($path);

Get an object by id

$index->object($id);

Insert a single object

$index->insert($object);

Remove an object by id

$index->remove($id);

Build the index

$index->buildIndex();

Full Example

$dim = 10;
$objects = [];
for ($i = 0; $i < 100; $i++) {
$object = [];
for ($j = 0; $j < $dim; $j++) {
$object[] = rand(0, 100);
}
$objects[] = $object;
}
$index = newNgt\Index($dim);
$index->batchInsert($objects);
$query = $objects[0];
$result = $index->search($query, size: 3);
foreach ($resultas$res) {
print($res['id'] . ', ' . $res['distance'] . "\n");
}

Index Options

Defaults shown below

useNgt\DistanceType;
useNgt\ObjectType;
newNgt\Index(
$dimensions,
edgeSizeForCreation: 10,
edgeSizeForSearch: 40,
distanceType: DistanceType::L2, // L1, L2, Hamming, Angle, Cosine, NormalizedAngle, NormalizedCosine, Jaccard
objectType: ObjectType::Float // Float, Float16, Integer
);

Credits

This library is modeled after NGT’s Python API.

History

View the changelog

Contributing

Everyone is encouraged to help improve this project. Here are a few ways you can help:

• Report bugs
• Fix bugs and submit pull requests
• Write, clarify, or fix documentation
• Suggest or add new features

To get started with development:

git clone https://github.com/ankane/ngt-php.git
cd ngt-php
composer install
composer test