NEExT is a powerful Python framework for graph analysis, embedding computation, and machine learning on graph-structured data. It provides a unified interface for working with different graph backends (NetworkX and iGraph), computing node features, generating graph embeddings, and training machine learning models.
Detailed documentation is available in the docs
directory. Build it locally or visit the online documentation at NEExT Documentation.
-
Flexible Graph Handling
- Support for both NetworkX and iGraph backends
- Automatic graph reindexing and largest component filtering
- Node sampling capabilities for large graphs
- Rich attribute support for nodes and edges
-
Comprehensive Node Features
- PageRank
- Degree Centrality
- Closeness Centrality
- Betweenness Centrality
- Eigenvector Centrality
- Clustering Coefficient
- Local Efficiency
- LSME (Local Structural Motif Embeddings)
-
Graph Embeddings
- Approximate Wasserstein
- Exact Wasserstein
- Sinkhorn Vectorizer
- Customizable embedding dimensions
-
Machine Learning Integration
- Classification and regression support
- Dataset balancing options
- Cross-validation with customizable splits
- Feature importance analysis
NEExT allows you to define and compute your own custom node feature functions alongside the built-in ones. This provides great flexibility for experimenting with novel graph metrics.
Defining a Custom Feature Function:
Your custom feature function must adhere to the following structure:
- Input: It must accept a single argument, which will be a
graph
object. This object provides access to the graph's structure (nodes, edges) and properties (e.g.,graph.nodes
,graph.graph_id
,graph.G
which is the underlying NetworkX or iGraph object). - Output: It must return a
pandas.DataFrame
with the following specific columns in order:"node_id"
: Identifiers for the nodes for which features are computed."graph_id"
: The identifier of the graph to which these nodes belong.- One or more feature columns: These columns should contain the computed feature values. The naming convention for these columns should ideally follow the pattern
your_feature_name_0
,your_feature_name_1
, etc., if your feature has multiple components or is expanded over hops (though a single feature column likeyour_feature_name
is also acceptable).
Example:
Here's how you can define a simple custom feature function and use it:
import pandas as pd
# 1. Define your custom feature function
# This function must be defined at the top level of your script/module
# if you plan to use multiprocessing (n_jobs != 1).
def my_node_degree_squared(graph):
nodes = list(graph.nodes) # or range(graph.G.vcount()) for igraph if nodes are 0-indexed
graph_id = graph.graph_id
if hasattr(graph.G, 'degree'): # Handles both NetworkX and iGraph
if isinstance(graph.G, nx.Graph): # NetworkX
degrees = [graph.G.degree(n) for n in nodes]
else: # iGraph
degrees = graph.G.degree(nodes)
else:
raise TypeError("Graph object does not have a degree method.")
degree_squared_values = [d**2 for d in degrees]
df = pd.DataFrame({
'node_id': nodes,
'graph_id': graph_id,
'degree_sq_0': degree_squared_values
})
# Ensure the correct column order
return df[['node_id', 'graph_id', 'degree_sq_0']]
# 2. Prepare the list of custom feature methods
my_feature_methods = [
{"feature_name": "my_degree_squared", "feature_function": my_node_degree_squared}
]
# 3. Pass it to compute_node_features
# Initialize NEExT and load your graph_collection as shown in the Quick Start
# nxt = NEExT()
# graph_collection = nxt.read_from_csv(...)
features = nxt.compute_node_features(
graph_collection=graph_collection,
feature_list=["page_rank", "my_degree_squared"], # Include your custom feature name
feature_vector_length=3, # Applies to built-in features that use it
my_feature_methods=my_feature_methods
)
print(features.features_df.head())
When you include "my_degree_squared"
in the feature_list
and provide my_feature_methods
, NEExT will automatically register and compute your custom function. If "all"
is in feature_list
, your custom registered function will also be included in the computation.
pip install NEExT
# Clone the repository
git clone https://github.com/ashdehghan/NEExT.git
cd NEExT
# Install with development dependencies
pip install -e ".[dev]"
# For running tests
pip install -e ".[test]"
# For building documentation
pip install -e ".[docs]"
# For running experiments
pip install -e ".[experiments]"
# Install all components
pip install -e ".[dev,test,docs,experiments]"
from NEExT import NEExT
# Initialize the framework
nxt = NEExT()
nxt.set_log_level("INFO")
# Load graph data
graph_collection = nxt.read_from_csv(
edges_path="edges.csv",
node_graph_mapping_path="node_graph_mapping.csv",
graph_label_path="graph_labels.csv",
reindex_nodes=True,
filter_largest_component=True,
graph_type="igraph"
)
# Compute node features
features = nxt.compute_node_features(
graph_collection=graph_collection,
feature_list=["all"],
feature_vector_length=3
)
# Compute graph embeddings
embeddings = nxt.compute_graph_embeddings(
graph_collection=graph_collection,
features=features,
embedding_algorithm="approx_wasserstein",
embedding_dimension=3
)
# Train a classifier
model_results = nxt.train_ml_model(
graph_collection=graph_collection,
embeddings=embeddings,
model_type="classifier",
sample_size=50
)
NEExT supports node sampling for handling large graphs:
# Load graphs with 70% of nodes
graph_collection = nxt.read_from_csv(
edges_path="edges.csv",
node_graph_mapping_path="node_graph_mapping.csv",
node_sample_rate=0.7 # Use 70% of nodes
)
# Compute feature importance
importance_df = nxt.compute_feature_importance(
graph_collection=graph_collection,
features=features,
feature_importance_algorithm="supervised_fast",
embedding_algorithm="approx_wasserstein"
)
NEExT includes several pre-built experiments in the examples/experiments
directory:
Investigates the effect of node sampling on classifier accuracy:
cd examples/experiments
python node_sampling_experiments.py
src_node_id,dest_node_id
0,1
1,2
...
node_id,graph_id
0,1
1,1
2,2
...
graph_id,graph_label
1,0
2,1
...
# Run all tests
pytest
# Run with coverage
pytest --cov=NEExT
# Run specific test file
pytest tests/test_node_sampling.py
cd docs
make html
The project uses several tools for code quality:
# Format code
black .
# Sort imports
isort .
# Check style
flake8 .
# Type checking
mypy .
- Fork the repository
- Create a feature branch
- Make your changes
- Run tests
- Submit a pull request
This project is licensed under the MIT License - see the LICENSE file for details.
- Ash Dehghan - ash.dehghan@gmail.com
- NetworkX team for the graph algorithms
- iGraph team for the efficient graph operations
- Scikit-learn team for machine learning components
For questions and support:
- Email: ash@anomalypoint.com
- GitHub Issues: NEExT Issues
- 0.1.0
- Initial release
- Basic graph operations
- Node feature computation
- Graph embeddings
- Machine learning integration