# CLAM: Clustered Learning of Approximate Manifolds (v0.22.3)
CLAM is a Rust/Python library for learning approximate manifolds from data.
It is designed to be fast, memory-efficient, easy to use, and scalable for big data applications.
CLAM provides utilities for fast search (Cakes) and anomaly detection (Chaoda).
As of writing this document, the project is still in a pre-1.0 state.
This means that the API is not yet stable and breaking changes may occur frequently.
## Usage
CLAM is a library crate so you can add it to your crate using `cargo add abd_clam@0.22.3`.
Here is a simple example of how to use CLAM to perform nearest neighbors search:
```rust
use symagen::random_data;
use abd_clam::{knn, rnn, Cakes, PartitionCriteria, VecDataset};
/// Euclidean distance function.
///
/// This function is used to compute the distance between two points for the purposes
/// of this demo. You can use your own distance function instead. The required
/// signature is `fn(T, T) -> U` where `T` is the type of the points (must
/// implement `Send`, `Sync` and `Copy`) and `U` is a `Number` type (e.g. `f32`)
/// from the `distances` crate.
fn euclidean(x: &[f32], y: &[f32]) -> f32 {
x.iter()
.zip(y.iter())
.map(|(a, b)| a - b)
.map(|v| v * v)
.sum::<f32>()
.sqrt()
}
// Some parameters for generating random data.
let seed = 42;
let (cardinality, dimensionality) = (1_000, 10);
let (min_val, max_val) = (-1., 1.);
/// Generate some random data. You can use your own data here.
let data: Vec<Vec<f32>> = random_data::random_f32(cardinality, dimensionality, min_val, max_val, seed);
// We will use the first point in data as our query, and we will perform
// RNN search with a radius of 0.05 and KNN search for the 10 nearest neighbors.
let query: Vec<f32> = data[0].clone();
let radius: f32 = 0.05;
let k = 10;
// We need the contents of data to be &[f32] instead of Vec<f32>. We will rectify this
// in CLAM by extending the trait bounds of some types in CLAM.
let data: Vec<&[f32]> = data.iter().map(Vec::as_slice).collect::<Vec<_>>();
let name = "demo".to_string(); // The name of the dataset.
let is_metric_expensive = false; // We will assume that our distance function is cheap to compute.
// The metric function itself will be given to Cakes.
let data = VecDataset::new(name, data, euclidean, is_metric_expensive);
// We will use the default partition criteria for this example. This will partition
// the data until each Cluster contains a single unique point.
let criteria = PartitionCriteria::default();
// The Cakes struct provides the functionality described in the CHESS paper.
// This line performs a non-trivial amount of work.
let model = Cakes::new(data, Some(seed), criteria);
// We will soon add the ability to save and load models, but for now we will
// just use the model we just created.
// We can now perform RNN search on the model.
let rnn_results: Vec<(usize, f32)> = model.rnn_search(&query, radius, rnn::Algorithm::Clustered);
assert!(!rnn_results.is_empty());
// We can also perform KNN search on the model.
let knn_results: Vec<(usize, f32)> = model.knn_search(&query, k, knn::Algorithm::RepeatedRnn);
assert!(knn_results.len() >= k);
// Both results are a Vec of 2-tuples where the first element is the index of the point
// in the dataset and the second element is the distance from the query point.
```
## License
- MIT
## References
- [CHESS](https://arxiv.org/abs/1908.08551)
- [CHAODA](https://arxiv.org/abs/2103.11774)
## Citation
TODO