semantic-embeddings

semantic-embeddings is the official implementation of GRaCE algorithm for generating rank-based semantic and contextual embeddings from top-K similarity lists.

This library implements the RaDE and GRaCE algorithms, which use graph-based measures to create interpretable, effective, and unsupervised embeddings for retrieval, clustering, classification, and visualization.

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🔍 Overview

Unlike traditional embedding techniques that require raw features or supervised training, this package builds representations entirely from ranked similarity lists (e.g., from a kNN graph or retrieval system). Each embedding dimension corresponds to a "leader" (reference node).

Key benefits:

• Unsupervised: No labels or ground truth needed.
• Explainable: Embedding dimensions are semantically grounded.
• Versatile: Works for text, images, graphs—any domain with top-K similarities.

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📦 Installation

pip install semantic-embeddings

Dependencies:

• numpy
• tqdm

Requires Python ≥ 3.7.

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🧠 Algorithms

RaDE (Rank-based Diffusion Embedding)

• Selects leaders by propagating rank-based affinities through a diffusion process.

GRaCE (Graph and Rank-based Contextual Embeddings)

• Extends RaDE with unsupervised effectiveness estimation (e.g., Reciprocal Density, Accumulated JacMax) and rank correlation measures (e.g., Reciprocal Distance, JacMax).

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🛠 Usage

Input Format

Your input must be a .txt file with one ranked list per line (space-separated item IDs):

15 3 8 22 7 9 ...
3 2 11 5 6 ...
...

Each line is a query, and each number is a retrieved item.

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RaDE Example

from sembeddings import RaDE

# Initialize
rade = RaDE(rks_path="data/ranked_lists.txt", rks_size_L=20)

# Compute internal structure
rade.fit(num_candidates=1000, num_leaders=128, t=2)

# Get embedding vectors
embeddings = rade.transform()

# Or do both in one call
embeddings = rade.fit_transform(num_candidates=1000, num_leaders=128, t=2)

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GRaCE Example

from sembeddings import GRaCE

grace = GRaCE(
    rks_path="data/ranked_lists.txt",
    top_K=20,
    correlation_measure="jacmax",  # or "reciprocal"
    estimation_measure="reciprocal_density",  # or "accjacmax"
    alpha=0.95
)

# Compute internal structure
grace.fit(num_leaders=128)

# Get embedding vectors
embeddings = grace.transform()

# Or do both in one call
embeddings = grace.fit_transform(num_leaders=128)

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🔬 Example Applications

Retrieval

from sklearn.metrics.pairwise import cosine_similarity

query_idx = 0
sims = cosine_similarity(embeddings)
top_k = sims[query_idx].argsort()[::-1][1:11]
print("Top-10 results for query:", top_k)

Clustering

from sklearn.cluster import KMeans

kmeans = KMeans(n_clusters=5).fit(embeddings)
print(kmeans.labels_)

Classification

from sklearn.linear_model import LogisticRegression
from sklearn.model_selection import train_test_split

X_train, X_test, y_train, y_test = train_test_split(embeddings, labels)
clf = LogisticRegression(max_iter=1000).fit(X_train, y_train)
print("Accuracy:", clf.score(X_test, y_test))

Visualization

from sklearn.manifold import TSNE
import matplotlib.pyplot as plt

proj = TSNE(n_components=2).fit_transform(embeddings)
plt.scatter(proj[:, 0], proj[:, 1], c=labels, cmap="tab10")
plt.title("2D Visualization of RaDE Embeddings")
plt.show()

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📁 Package Structure

semantic-embeddings/
│
├── rade.py                 # RaDE implementation
├── grace.py                # GRaCE implementation
├── utils.py                # Ranked list reader
└── measures/
    ├── qpp.py              # Query performance prediction measures (AccJacMax, Reciprocal Density)
    └── correlation.py      # Rank correlation measures (JacMax, Reciprocal KNN)

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📚 Citation

If you use this library in your research, please cite:

GRaCE (Accepted, pending publication)

Almeida, T. C. C., Letício, G. R., Valem, L. P., Freitas, A., Pedronette, D. C. G.
Effective Graph and Rank-based Contextual Embeddings for Textual and Multimedia Data
2025 International Joint Conference on Neural Networks (IJCNN), Rome – Italy.

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RaDE

De Fernando, F. A., Pedronette, D. C. G., De Sousa, G. J., Valem, L. P., Guilherme, I. R.
RaDE: A Rank-based Graph Embedding Approach
15th International Conference on Computer Vision Theory and Applications (VISAPP), 2020.

RaDE+: A Semantic Rank-based Graph Embedding Algorithm
International Journal of Information Management Data Insights, 2022.

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🤝 Contact

• Thiago César Castilho Almeida: tc.almeida@unesp.br
• Lucas Pascotti Valem: lucaspascottivalem@gmail.com
• Daniel Carlos Guimarães Pedronette: pedronette@gmail.com