LycorisAD

An elegant outlier detection algorithm framework based on AutoEncoder.


Keywords
anomaly-detection, autoencoder, outlier-detection
License
LGPL-3.0
Install
pip install LycorisAD==1.5.4

Documentation

logo

LycorisAD is an elegant outlier detection algorithm framework based on AutoEncoder.

The neural network is built with LycorisNet, and the threshold of reconstruction error is calculated by genetic algorithm (based on deap).

Features

  • Lightweight and elegant.
  • Need not to manually design the structure of the autoencoder.
  • Provide minimalist APIs to make development more efficient.

Installation

The project is based on LycorisNet, and the installation of LycorisNet can be found here.

pip install LycorisAD

Documents

The APIs provided by AnomalyDetection (from LycorisAD import AnomalyDetection):

Function Description Inputs Returns
AnomalyDetection(config) Constructor. config: The configuration information, including 12 configuration fields. An object of the class AnomalyDetection.
encode(data, normals, anomalies) Self-encode the samples and calculate the threshold. data: Normal samples for self-encoding.
normals: Normal samples used to calculate the threshold.
anomalies: Anomaly samples used to calculate the threshold.
detect(data) Detect samples. data: Samples to be detected. The results after detecting the samples are returned as a list. There are two fields, the first is a Boolean value, and the second is the reconstruction error. Where 'True' indicates normal and 'False' indicates anomaly.
save(path1, path2) Save the model and related configurations. path1: The path to store the model.
path2: The path to store the configurations.
@staticmethod
load(path1, path2)
Import pre-trained models and related configurations. path1: The path to import the model.
path2: The path to import the configurations.
set_config(config) Set the configuration information of AnomalyDetection. config: The configuration information, including 12 configuration fields.
set_lr(learning_rate) Set the learning rate of the AutoEncoder. learning_rate: The learning rate of the AutoEncoder.
set_workers(workers) Set the number of worker threads to train the model. workers: The number of worker threads.
get_threshold() Get the threshold.
@staticmethod
version()
Returns the version information of AnomalyDetection.

Configurable fields:

Field Description Default
capacity Capacity of LycorisNet.
dimension Dimension of samples.
nodes The number of hidden nodes added for each neural network.
connections The number of connections added for each neural network.
depths Total layers of each neural network.
batch_size Batch size.
epoch Epoch.
evolution Number of LycorisNet evolutions. 0
population Population in the genetic algorithm. 256
generation Generation in the genetic algorithm. 16
weight The weights used to calculate the threshold.
The first parameter determines the prediction accuracy of normal samples, while the second parameter determines that of anomaly samples.
[1, 1]
verbose Whether to output intermediate information. False

Examples

  • MNIST

For a description of the data and its source, see here.

Import the dependent modules:

from LycorisAD import AnomalyDetection
import scipy.io as sio
import random
from sklearn.metrics import roc_auc_score

Read the data and divide it:

X = sio.loadmat('mnist.mat')["X"]
X = (X + 138) / 393.0

normal = X[:6903]
random.shuffle(normal)
normal = normal[:6900]

anomaly = X[6903:]
random.shuffle(anomaly)

data1 = normal[:5560]
data2 = normal[5560:6210]
data3 = anomaly[:630]

test_normal = normal[6210:]
test_anomaly = anomaly[630:]

Prepare the configuration information and instantiate the AnomalyDetection object:

conf = {"capacity": 64, "dimension": 100, "nodes": 300, "connections": 6000, "depths": 4, "batch_size": 8,
        "epoch": 1, "evolution": 1, "verbose": True}
lad = AnomalyDetection(conf)

Self-encoding:

lad.encode(data1, data2, data3)

Calculate the AUC on the test set:

result1 = lad.detect(test_normal)
result2 = lad.detect(test_anomaly)

auc1 = [0] * len(result1) + [1] * len(result2)
auc2 = []
for item in (result1 + result2):
    if item[0]:
        auc2.append(0)
    else:
        auc2.append(1)
print("AUC:", roc_auc_score(auc1, auc2))
  • More examples will be released in the future.

License

LycorisAD is released under the LGPL-3.0 license. By using, distributing, or contributing to this project, you agree to the terms and conditions of this license.