A Vector Database (Vector DB) is a specialized type of database designed to store, index, and retrieve vector embeddings efficiently. These embeddings are numerical representations of data (such as text, images, audio, or video) in high-dimensional space, enabling fast and accurate similarity searches.
Traditional databases (SQL, NoSQL) are not optimized for searching similarity between high-dimensional vectors. A Vector DB is designed specifically for tasks like:
Would you like an example of how to use a Vector DB in code? 🚀
Before data can be stored in a vector database, it must first be converted into vector embeddings. This is done using machine learning models that transform raw data (text, images, audio, etc.) into high-dimensional numerical representations.
For text-based applications (e.g., search engines, chatbots, recommendation systems), words or sentences need to be embedded into vectors.
pythonfrom openai import OpenAI client = OpenAI(api_key="your_api_key") response = client.embeddings.create( model="text-embedding-ada-002", input="How does a vector database work?" ) vector = response['data'][0]['embedding'] print(vector[:5]) # Prints first 5 dimensions of the embedding
For image-based applications (e.g., reverse image search, object recognition), deep learning models convert images into vector representations.
pythonimport torch import clip from PIL import Image # Load the model device = "cuda" if torch.cuda.is_available() else "cpu" model, preprocess = clip.load("ViT-B/32", device=device) # Load and process image image = preprocess(Image.open("example.jpg")).unsqueeze(0).to(device) # Generate vector embedding with torch.no_grad(): image_embedding = model.encode_image(image) print(image_embedding.shape) # Output: torch.Size([1, 512])
For audio-based applications (e.g., voice search, speaker recognition), raw audio is first converted into a spectrogram, then embedded into a vector.
pythonimport whisper model = whisper.load_model("base") audio_embedding = model.encode("example.wav") print(audio_embedding.shape) # Output: (number of tokens, embedding size)
For structured data (like relational databases), you can either:
pythonfrom sklearn.decomposition import PCA import numpy as np data = np.random.rand(100, 10) # Example tabular data (100 rows, 10 features) pca = PCA(n_components=5) # Reduce to 5 dimensions vectorized_data = pca.fit_transform(data) print(vectorized_data.shape) # Output: (100, 5)
After converting the data, it is stored in a vector database like FAISS, Pinecone, or Milvus. Here’s an example using FAISS:
pythonimport faiss import numpy as np # Sample 100 vectors of size 128 vector_data = np.random.rand(100, 128).astype('float32') # Create an index index = faiss.IndexFlatL2(128) # L2 distance (Euclidean) index.add(vector_data) # Add vectors to the database # Query the nearest neighbor query_vector = np.random.rand(1, 128).astype('float32') _, result_indices = index.search(query_vector, 5) # Get 5 closest vectors print(result_indices) # Indices of closest vectors
🔹
Data conversion is the first step in using a Vector
DB.
🔹 Different
AI models convert text, images, audio, and structured
data into
vector embeddings.
🔹 These
embeddings are then stored, indexed, and queried
efficiently.
Would you like help setting up a Vector DB for a specific use case? 🚀
If you don’t want to use AI models to convert data into vector embeddings, you can explore alternative methods based on mathematical, statistical, or algorithmic techniques. These approaches may not capture semantic meaning as well as AI models, but they can still be effective for certain use cases.
Instead of AI-generated embeddings, you can manually extract features from the data using domain knowledge.
📌 Example (TF-IDF Vectorization in Python)
pythonfrom sklearn.feature_extraction.text import TfidfVectorizer texts = ["vector databases are fast", "databases store information"] vectorizer = TfidfVectorizer() vectors = vectorizer.fit_transform(texts) print(vectors.toarray()) # Prints a matrix of TF-IDF values
Pros:
Simple, interpretable, computationally efficient.
Cons:
Doesn’t capture meaning, lacks context awareness.
You can transform structured/tabular data into vector form using mathematical methods.
📌 Example (Using PCA to Reduce a 10D Dataset to 3D)
pythonfrom sklearn.decomposition import PCA import numpy as np data = np.random.rand(100, 10) # 100 rows, 10 features pca = PCA(n_components=3) vectors = pca.fit_transform(data) print(vectors.shape) # (100, 3)
Pros:
Works well for numerical data, reduces storage
needs.
Cons:
May lose some information, not suitable for
non-numeric data.
Instead of AI embeddings, you can use hash functions to convert data into numerical representations.
📌 Example (Using LSH for Text Similarity)
pythonfrom datasketch import MinHash text1 = "vector databases are efficient" text2 = "databases store vectorized data" m1, m2 = MinHash(), MinHash() for word in text1.split(): m1.update(word.encode('utf8')) for word in text2.split(): m2.update(word.encode('utf8')) print(m1.jaccard(m2)) # Output: similarity score between 0 and 1
Pros:
Fast, memory-efficient, great for
approximate nearest neighbor (ANN)
search.
Cons:
Less precise than AI-based embeddings.
If you have categorical (non-numeric) data, you can convert it into numerical vectors manually.
📌 Example (One-Hot Encoding in Pandas)
pythonimport pandas as pd df = pd.DataFrame({'Category': ['A', 'B', 'C', 'A']}) one_hot = pd.get_dummies(df['Category']) print(one_hot)
Pros:
Simple, effective for structured data.
Cons:
Can lead to large vectors for high-cardinality data.
If you want to extract numerical features from audio without AI models, you can use Fourier transforms or statistical methods.
📌 Example (Extracting MFCC Features from an Audio File)
pythonimport librosa audio_path = "audio.wav" y, sr = librosa.load(audio_path) mfcc_features = librosa.feature.mfcc(y=y, sr=sr, n_mfcc=13) print(mfcc_features.shape) # (13, time frames)
Pros:
Works well for
speech recognition
and
audio classification.
Cons:
Requires signal processing expertise.
Instead of deep learning, you can extract basic image features using traditional computer vision techniques.
📌 Example (Using OpenCV to Extract HOG Features)
pythonimport cv2 import numpy as np img = cv2.imread("image.jpg", cv2.IMREAD_GRAYSCALE) hog = cv2.HOGDescriptor() features = hog.compute(img) print(features.shape) # Vectorized image
Pros:
Computationally faster than deep learning models.
Cons:
Less accurate than CNN-based embeddings.
For some applications, a logical set of rules can replace vector embeddings.
Example Use Case:
Instead of
embedding medical text, a rule-based system might
check for
keyword matches
in medical databases.
If you
don’t want to use AI models, you can still convert data into vectors using: ✔
Statistical & mathematical methods (PCA,
TF-IDF, LSH, MinHash)
✔
Manual feature engineering (One-hot encoding,
Histograms, MFCC)
✔
Traditional signal processing & computer vision
(HOG, FFT, ZCR)
✔
Rule-based representations (Ontologies,
Taxonomies)
Would you like a recommendation based on your specific use case? 🚀
Yes! Elasticsearch (ES) is a great alternative to dedicated vector databases when handling text, image, or structured data without fully relying on AI models.
Elasticsearch is traditionally used for keyword-based searches, but it also supports vector search via k-NN (k-Nearest Neighbors) and dense vector fields. This makes it a strong choice for hybrid search (combining keyword + vector search).
Elasticsearch doesn’t directly convert data into vectors, but it provides ways to index and query them efficiently. You can handle conversion manually before storing data in ES.
✔
Text Data: Convert text into vectors using
TF-IDF, BM25, or dense embeddings
✔
Image Data: Convert images into feature vectors before
indexing
✔
Audio Data: Convert spectrograms or statistical features into
vectors
✔
Structured Data: Store numerical features directly as vectors
Once the data is vectorized, ES can store it as a dense vector field and perform similarity searches.
If you want good text retrieval without AI, BM25 and TF-IDF scoring models in Elasticsearch can replace vector embeddings.
📌 Example: Using BM25 for Text Search
jsonPUT my_index { "settings": { "analysis": { "analyzer": { "standard_analyzer": { "type": "standard" } } } }, "mappings": { "properties": { "text": { "type": "text", "analyzer": "standard_analyzer" } } } }
✔
Advantages: Fast, well-optimized for traditional search
❌
Limitations: Doesn't capture
semantic meaning
like AI embeddings
If you precompute embeddings (e.g., using CLIP for images or Sentence-BERT for text), Elasticsearch can store and search them.
📌 Example: Storing Dense Vectors in Elasticsearch
jsonPUT my_vector_index { "mappings": { "properties": { "text_embedding": { "type": "dense_vector", "dims": 768 } } } }
jsonPOST my_vector_index/_search { "size": 5, "query": { "script_score": { "query": { "match_all": {} }, "script": { "source": "cosineSimilarity(params.query_vector, 'text_embedding') + 1.0", "params": { "query_vector": [0.1, 0.2, ..., 0.8] } } } } }
✔ Advantages:
❌ Limitations:
Elasticsearch is powerful for hybrid search, meaning you can combine:
📌 Example: Hybrid Search Query
jsonPOST my_index/_search { "query": { "bool": { "should": [ { "match": { "text": "vector database" } }, # BM25 keyword search { "script_score": { # Vector similarity search "query": { "match_all": {} }, "script": { "source": "cosineSimilarity(params.query_vector, 'text_embedding') + 1.0", "params": { "query_vector": [0.1, 0.2, ..., 0.8] } } } } ] } } }
This boosts relevance by combining both traditional search and semantic search.
✅ Use Elasticsearch if:
❌ Avoid Elasticsearch if:
Feature | Elasticsearch | Vector Databases (FAISS, Pinecone, Milvus) |
---|---|---|
Text Search | ✅ Best for keyword-based search | ❌ Not designed for traditional text search |
Hybrid Search | ✅ Supports both BM25 + Vectors | ❌ Mostly focuses on pure vector search |
Vector Search | ⚠️ Good but less optimized | ✅ Highly optimized for ANN search |
Scalability | ✅ Scales well for real-time apps | ✅ Scales better for dense vectors |
Ease of Use | ✅ Easy setup for search applications | ❌ Requires additional AI model setup |
🚀 Best Use Case for Elasticsearch: If you need a search engine that blends keyword and vector search without relying 100% on AI.
Would you like a hands-on code example for setting up vector search with Elasticsearch? 🔥
State-of-the-art (SOTA) similarity refers to the most advanced and efficient methods for measuring how similar two pieces of data are, such as text, images, audio, or structured data. These methods use the latest advancements in machine learning, mathematics, and indexing techniques to ensure high accuracy and speed.
Many real-world applications rely on finding similar items:
The most advanced similarity methods rely on:
Let’s break each down.
Traditional distance-based similarity methods compare data points in a numerical space.
Metric | Formula | Best For |
---|---|---|
Cosine Similarity | ( \cos(\theta) = \frac{A \cdot B}{ | |
Euclidean Distance | d(A,B)=∑(Ai−Bi)2 | Images, 3D data |
Manhattan Distance | ( d(A, B) = \sum | A_i - B_i |
Jaccard Similarity | ( J(A, B) = \frac{ | A \cap B |
📌 Example: Cosine Similarity in Python
pythonfrom sklearn.metrics.pairwise import cosine_similarity import numpy as np vec1 = np.array([[1, 2, 3]]) vec2 = np.array([[2, 3, 4]]) similarity = cosine_similarity(vec1, vec2) print(similarity) # Output: [[0.9925]]
✅
Pros: Simple, interpretable, works well for small
datasets.
❌
Cons:
Slow for large-scale search
(e.g., millions of items).
Instead of manually computing distances, AI models can learn better representations (embeddings) to improve similarity accuracy.
Model | Type | Best For |
---|---|---|
BERT / SBERT | Text | NLP, Chatbots, Search |
OpenAI CLIP | Image & Text | Image retrieval, Captioning |
DINOv2 | Vision | Object detection, Face Recognition |
Whisper | Audio | Speech-to-text, Speaker Matching |
📌
Example: Using OpenAI’s
text-embedding-ada-002
Model for Similarity
pythonfrom openai import OpenAI client = OpenAI(api_key="your_api_key") query = "best restaurants in New York" response = client.embeddings.create(model="text-embedding-ada-002", input=query) embedding = response['data'][0]['embedding'] print(embedding[:5]) # Prints first 5 dimensions
✅
Pros: Captures
semantic meaning, robust to noise,
handles unstructured data.
❌
Cons: Requires
pre-training
and
vector storage
for efficient retrieval.
Traditional similarity search is slow for large datasets (millions of vectors). To solve this, ANN (Approximate Nearest Neighbors) algorithms speed up search by indexing vectors efficiently.
Algorithm | Library | Best Use Cases |
---|---|---|
HNSW (Hierarchical Navigable Small World) | FAISS, Milvus | High-speed large-scale retrieval |
IVF (Inverted File Index) | FAISS | Efficient clustering for billions of vectors |
LSH (Locality-Sensitive Hashing) | ScaNN, Annoy | Quick filtering for nearest neighbor search |
📌 Example: Using FAISS for Fast Vector Search
pythonimport faiss import numpy as np # Create random 128D vectors vector_data = np.random.rand(10000, 128).astype('float32') # Create an index index = faiss.IndexFlatL2(128) index.add(vector_data) # Query the 5 closest vectors query_vector = np.random.rand(1, 128).astype('float32') _, result_indices = index.search(query_vector, 5) print(result_indices) # Returns closest vector indices
✅
Pros:
Super fast, scalable for
millions of vectors.
❌
Cons: Needs
preprocessing
and
proper indexing strategies.
The best SOTA similarity methods combine multiple techniques:
📌 Example: Hybrid Search Using Elasticsearch
jsonPOST my_index/_search { "query": { "bool": { "should": [ { "match": { "text": "deep learning research" } }, # BM25 keyword search { "script_score": { # Vector similarity search "query": { "match_all": {} }, "script": { "source": "cosineSimilarity(params.query_vector, 'text_embedding') + 1.0", "params": { "query_vector": [0.1, 0.2, ..., 0.8] } } } } ] } } }
✅
Pros:
Best retrieval accuracy, works well in
real-world applications.
❌
Cons: More
computationally intensive, needs
efficient indexing.
🚀 The best similarity method depends on your dataset, speed needs, and accuracy goals:
✔
Small datasets
→ Use
Cosine Similarity or Jaccard Similarity
✔
Large-scale search
→ Use
FAISS (HNSW, IVF) or Milvus
✔
Text Search
→ Use
SBERT, BM25, or hybrid search (BM25 +
Vector)
✔
Image Search
→ Use
CLIP embeddings + FAISS
✔
Real-Time Applications
→ Use
Elasticsearch for Hybrid Search
Would you like a hands-on demo or code implementation for a specific similarity use case? 🚀
Elasticsearch supports dense vector fields for similarity search, but the optimal number of dimensions depends on your dataset size, search speed, and memory constraints.
✔
Max Dimensions:
Elasticsearch supports up to 1024
dimensions.
✔
Recommended Dimensions:
50–768 dimensions
(for efficiency).
✔
Best Practice:
Keep vectors
under 300 dimensions
for
better performance.
Dimensionality | Use Case | Performance Trade-off |
---|---|---|
10–50 | Simple keyword embedding (TF-IDF, LSH) | 🔹 Fastest, but low accuracy |
100–300 | General-purpose NLP (SBERT, sentence embeddings) | ✅ Best for most Elasticsearch workloads |
512–768 | Transformer-based embeddings (BERT, CLIP) | ⚠️ Requires more RAM & compute |
1024+ | Specialized AI models (OpenAI embeddings) | ❌ Not recommended for Elasticsearch (FAISS is better) |
✔
Try reducing vector size
(e.g., use PCA to compress high-dimensional
embeddings).
✔
Use efficient indexing techniques
(like HNSW for ANN search).
✔
Combine keyword search (BM25) + vector
search
for better results.
jsonPUT my_index { "mappings": { "properties": { "text_embedding": { "type": "dense_vector", "dims": 300 } } } }
Would you like help optimizing Elasticsearch for vector search in your specific use case? 🚀
The number of dimensions in a vector represents how much information is stored about the data. However, higher dimensions can slow down search performance, so finding the right balance is important.
Let’s break it down based on different use cases:
Number of Dimensions | When to Use It? | Pros & Cons |
---|---|---|
10–50 | Simple search (e.g., TF-IDF, keyword embeddings) | ✅ Very fast search, ❌ Low accuracy |
100–300 | Most NLP applications (e.g., SBERT, sentence embeddings) | ✅ Good balance of speed & accuracy |
512–768 | Advanced AI models (e.g., BERT, OpenAI embeddings) | ✅ High accuracy, ❌ Slower & requires more memory |
1024+ | Complex deep learning models (e.g., GPT, specialized AI search) | ❌ Not recommended for Elasticsearch (better to use FAISS or Milvus) |
📌 For Elasticsearch, try to keep your vector dimensions below 300 for optimal performance. 🚀
Would you like help choosing the right embedding model based on your use case? 😊
If Elasticsearch isn’t the best option for your use case, here’s what I recommend based on vector dimensions and search needs:
Dimension Range | Best Use Case | Recommended Alternative | Why? |
---|---|---|---|
10–50 | Simple search (TF-IDF, keyword search, LSH) | ✅ Elasticsearch (BM25 + TF-IDF) | Elasticsearch is great for low-dimensional data, since keyword search dominates in this range. |
100–300 | General NLP (SBERT, small AI models, text embeddings) | ✅ Elasticsearch (dense_vector) OR FAISS (HNSW) | Elasticsearch works well here, but FAISS is better if you need faster large-scale search. |
512–768 | Deep learning models (BERT, CLIP, sentence transformers) | ✅ FAISS (HNSW or IVF) OR Pinecone | Elasticsearch slows down, so FAISS or Pinecone are better for handling high-dimensional vectors. |
1024+ | AI-powered similarity search (GPT, complex embeddings) | ✅ Milvus, Weaviate, or Vespa | Elasticsearch is not designed for this. Milvus or Weaviate handle ultra-high-dim vectors efficiently. |
🚀 If you're dealing with:
If You Need... | Best Choice |
---|---|
Traditional keyword search | ✅ Elasticsearch (BM25, TF-IDF) |
Fast vector search for small datasets | ✅ Elasticsearch (dense_vector, k-NN) |
Scalable AI-powered similarity search | ✅ FAISS (HNSW, IVF) |
Production-ready vector search | ✅ Pinecone, Weaviate, Vespa |
Ultra-high-dimensional vector search (1024+ D) | ✅ Milvus, Weaviate, Vespa |
Would you like help choosing a specific solution for your dataset? 🚀
Reducing the dimensionality of vectors is important for performance optimization and storage efficiency while maintaining as much useful information as possible. High-dimensional vectors (e.g., 512+ dimensions) can slow down search operations, increase storage costs, and lead to the curse of dimensionality—where distances between vectors become less meaningful.
📌 Example: Searching in FAISS with 128D vectors is much faster than 1024D vectors, especially with billions of entries.
📌 Example:
For millions of vectors, this adds up significantly.
📌 Example: If you're using Euclidean distance, differences between similar and dissimilar vectors become negligible in 1000+ dimensions.
📌 Example: PCA (Principal Component Analysis) helps eliminate weakly contributing dimensions while keeping meaningful variations.
📌 Example: Reduce a 512D vector to 128D using PCA
pythonfrom sklearn.decomposition import PCA import numpy as np vectors = np.random.rand(1000, 512) # 1000 vectors with 512 dimensions pca = PCA(n_components=128) # Reduce to 128 dimensions reduced_vectors = pca.fit_transform(vectors) print(reduced_vectors.shape) # Output: (1000, 128)
📌 Example: Using an Autoencoder for Dimensionality Reduction
pythonfrom tensorflow import keras encoder = keras.Sequential([ keras.layers.Dense(256, activation='relu', input_shape=(512,)), keras.layers.Dense(128, activation='relu') ])
✅
Better than PCA for complex datasets.
❌
Requires training data & more
computation.
📌 Example: If using BERT embeddings (768D), keep only first 300D:
pythonvector_bert = vector_bert[:300] # Truncate to first 300 dimensions
✅
Fast & simple
❌
Might discard important information
Scenario | Recommendation |
---|---|
Using Elasticsearch for vector search | ✅ Reduce to ≤300D (best for performance) |
Using FAISS or Milvus | ✅ Keep 512D max unless needed |
Handling billions of vectors | ✅ Reduce to 128D-256D for speed |
Need highest accuracy | ❌ Do NOT reduce (keep original embeddings) |
Would you like help choosing the best method for your specific dataset? 🚀
When using Principal Component Analysis (PCA) for dimensionality reduction, the right number of output dimensions depends on how much information (variance) you want to keep while reducing computational cost.
📌 Example: Choosing the Number of Components Based on 95% Variance
pythonfrom sklearn.decomposition import PCA import numpy as np # Generate random high-dimensional data (1000 samples, 512 features) data = np.random.rand(1000, 512) # Fit PCA without specifying dimensions pca = PCA().fit(data) # Calculate cumulative explained variance cumulative_variance = np.cumsum(pca.explained_variance_ratio_) # Find the number of dimensions needed to keep 95% variance n_components = np.argmax(cumulative_variance >= 0.95) + 1 print(f"Optimal dimensions for 95% variance: {n_components}")
✅
Advantage:
Ensures minimal
loss of information
while improving
efficiency.
❌
Disadvantage:
Requires
trial and error.
📌 Example: Plotting PCA Components to Find the Elbow Point
pythonimport matplotlib.pyplot as plt # Plot variance explained by each component plt.plot(range(1, len(cumulative_variance) + 1), cumulative_variance, marker='o') plt.xlabel('Number of Components') plt.ylabel('Cumulative Explained Variance') plt.title('PCA Scree Plot') plt.grid() plt.show()
✅
Advantage:
Visual
and
intuitive
way to pick the right dimensions.
❌
Disadvantage:
May not be
precise
in all cases.
If you don’t want to calculate variance or plot a scree plot, you can use common benchmarks:
Original Dimensions | Recommended PCA Dimensions |
---|---|
50–100 | Keep 20–50 |
256 | Reduce to 128–200 |
512 | Reduce to 128–300 |
768 (BERT embeddings) | Reduce to 300–500 |
1024+ | Reduce to 512 or lower |
📌 Example: Directly Reducing 512D Vectors to 128D
pythonpca = PCA(n_components=128) data_reduced = pca.fit_transform(data)
✅
Advantage:
Simple
and works well for most cases.
❌
Disadvantage:
Not optimal for every dataset.
📌 Example: Selecting the Top 50 Important Features
pythonimportant_features = np.argsort(-pca.explained_variance_ratio_)[:50] data_selected = data[:, important_features]
✅
Advantage:
Keeps
only the most relevant
information.
❌
Disadvantage:
May require
manual feature selection.
Use Case | How to Pick Dimensions? |
---|---|
Want to maximize accuracy? | ✅ Keep 95% variance (best balance of speed & quality). |
Want to optimize performance? | ✅ Keep 85–90% variance (faster search, slight quality tradeoff). |
Need a quick approximation? | ✅ Use preset fixed values (e.g., reduce 512D → 128D). |
Have a large dataset & need the best efficiency? | ✅ Use the Scree Plot / Elbow Method. |
Would you like me to run PCA on your dataset or generate a scree plot for you? 🚀
Reducing 512 dimensions to 128 does not necessarily mean 95% variance is preserved. The number of dimensions you should keep depends on how much variance each principal component contributes, which is dataset-specific.
PCA selects the most important components that capture the highest variance. However, variance is not evenly distributed across all dimensions. In some datasets:
Instead of assuming 128D will keep 95% variance, we should calculate it.
📌 Example: Finding the Right Number of Dimensions for 95% Variance
pythonfrom sklearn.decomposition import PCA import numpy as np # Generate random high-dimensional data (1000 samples, 512 features) data = np.random.rand(1000, 512) # Fit PCA without specifying components pca = PCA().fit(data) # Calculate cumulative variance cumulative_variance = np.cumsum(pca.explained_variance_ratio_) # Find the number of components needed for 95% variance n_components_95 = np.argmax(cumulative_variance >= 0.95) + 1 print(f"Number of dimensions needed for 95% variance: {n_components_95}")
This will give the exact number of dimensions needed to preserve 95% of the variance.
If
n_components_95 > 128
, then reducing to
128D might result in losing important
information. In that case:
n_components_95 = 250
, you should
reduce to 250D instead of 128D.
n_components_95 = 120
, reducing to
128D is fine.
✅ Run
PCA without specifying dimensions.
✅ Find
where cumulative variance reaches 95%.
✅ Use that
as the
optimal dimension.
Would you like me to run this on your dataset to find the optimal dimension for 95% variance? 🚀
Yes! Using PCA without specifying dimensions is completely fine and is actually the best way to determine the optimal number of dimensions for preserving variance.
PCA Computes All Components by Default
n_components
,
PCA will compute all possible principal
components.
You Can Choose the Best Dimension Dynamically
Avoids Unnecessary Information Loss
n_components=128
without checking, you might
lose important information.
📌 Step 1: Fit PCA and Analyze Variance
pythonfrom sklearn.decomposition import PCA import numpy as np # Simulate high-dimensional data (1000 samples, 512 features) data = np.random.rand(1000, 512) # Fit PCA without specifying n_components pca = PCA().fit(data) # Compute cumulative explained variance cumulative_variance = np.cumsum(pca.explained_variance_ratio_) # Find number of components needed to retain 95% variance n_components_95 = np.argmax(cumulative_variance >= 0.95) + 1 print(f"Optimal number of dimensions for 95% variance: {n_components_95}")
📌 Step 2: Reduce Data to the Optimal Dimension
python# Apply PCA with the optimal number of dimensions pca_optimal = PCA(n_components=n_components_95) data_reduced = pca_optimal.fit_transform(data) print(f"Reduced data shape: {data_reduced.shape}")
✔
Using PCA without specifying
n_components
is a good approach.
✔
First, compute variance across all
dimensions.
✔
Then, decide how many dimensions to keep (e.g., 95%
variance).
✔
Finally, apply PCA with the selected number of
dimensions.
Would you like me to help with visualizing variance using a Scree plot? 📊🚀
cumulative_variance
in PCA?
cumulative_variance
refers to the
cumulative sum of explained variance ratios
from
Principal Component Analysis (PCA). It helps determine how many principal components
(dimensions)
retain the most important information
from the original data.
When you apply PCA, each new component captures some percentage of the total variance in the dataset. This is called the explained variance ratio.
📌 Example: Explained Variance Ratio
pythonpca = PCA().fit(data) print(pca.explained_variance_ratio_)
Output (example):
[0.40, 0.25, 0.15, 0.10, 0.05, ...]
This means:
cumulative_variance
)
Instead of looking at each component individually, we sum up the explained variance across components to see how much total variance is retained.
📌 Computing Cumulative Variance
pythonimport numpy as np # Compute cumulative variance cumulative_variance = np.cumsum(pca.explained_variance_ratio_) print(cumulative_variance)
Output:
[0.40, 0.65, 0.80, 0.90, 0.95, ...]
This means:
To find the smallest number of dimensions that retain 95% variance, we do:
python# Find number of components needed for 95% variance n_components_95 = np.argmax(cumulative_variance >= 0.95) + 1 print(f"Optimal dimensions for 95% variance: {n_components_95}")
✔ This gives the exact number of dimensions that keep 95% of the original data's variance.
✅
If
cumulative_variance
reaches 95% at 200 dimensions, you should reduce to
200D
instead of guessing (e.g., assuming 128D is
enough).
✅
Helps balance accuracy & performance
→ Fewer dimensions =
faster search, lower storage costs.
✅
Prevents information loss
by ensuring
enough variance is retained.
Would you like me to generate a Scree Plot to visualize how variance accumulates across dimensions? 📊🚀
pythonn_components_95 = np.argmax(cumulative_variance >= 0.95) + 1
This line finds the minimum number of dimensions required to retain at least 95% of the variance in PCA.
cumulative_variance >= 0.95
cumulative_variance
is a
numpy array
where each value represents
the total variance retained
up to that principal component.
cumulative_variance >= 0.95
creates a
boolean array
that tells us
which components have retained at least 95%
variance.
📌
Example:
cumulative_variance
pythoncumulative_variance = np.array([0.40, 0.65, 0.80, 0.90, 0.95, 0.97, 0.99]) print(cumulative_variance >= 0.95)
📌 Output (Boolean Mask)
[False, False, False, False, True, True, True]
👉 This tells us that the 5th component (index 4) is the first one that reaches 95% variance.
np.argmax(cumulative_variance >= 0.95)
np.argmax()
returns the index
of the
first
True
value
in the boolean array.
📌 Example:
pythonindex = np.argmax([False, False, False, False, True, True, True]) print(index) # Output: 4
👉 The 4th index (5th component) is the first one where variance reaches 95%.
+1
(Adjusting for 0-Based Indexing)
Since
Python arrays are 0-indexed
(the first element is at index
0
), we
add
+1
to
convert the index to the correct number of
components.
📌 Final Calculation
pythonn_components_95 = np.argmax(cumulative_variance >= 0.95) + 1 print(n_components_95) # Output: 5
👉 This means keeping 5 principal components will retain 95% variance.
pythonn_components_95 = np.argmax(cumulative_variance >= 0.95) + 1
✅
Finds the smallest number of dimensions
needed to keep
at least 95% variance.
✅
Uses
np.argmax()
to find the first index
where cumulative variance reaches 0.95.
✅
Adds
+1
because Python indexing starts from
0
.
Would you like me to generate a Scree Plot to visualize this process? 📊🚀
"Optimizing Vector Dimensions: PCA, Similarity Search, and Elasticsearch Alternatives"
The line:
pythondata = np.random.rand(1000, 512)
Generates a 2D NumPy array of random values with shape (1000, 512).
np.random.rand(1000, 512)
np.random.rand()
is a
NumPy function
that generates
random numbers
between
0 and 1.
(1000, 512)
means:
1000
→ Number of
rows
(samples or data points).
512
→ Number of
columns
(features or dimensions).
📌 Running:
pythonimport numpy as np data = np.random.rand(3, 5) # Small example print(data)
📌 Sample Output:
[[0.15 0.89 0.47 0.62 0.33] [0.78 0.56 0.12 0.91 0.44] [0.67 0.21 0.76 0.35 0.59]]
✅
Testing PCA
(e.g., reducing 512D to 128D).
✅
Simulating high-dimensional embeddings
(e.g., vector search).
✅
Training machine learning models
(before using real data).
Would you like me to modify this to generate real embeddings (e.g., using BERT or CLIP)? 🚀
The number of dimensions (features) in the following line of code:
pythondata = np.random.rand(1000, 512)
is 512.
np.random.rand(1000, 512)
creates a
2D NumPy array.
📌 Checking the Shape in Python
pythonimport numpy as np data = np.random.rand(1000, 512) print(data.shape) # Output: (1000, 512)
✔
Output:
(1000, 512)
→
1000 samples, each with 512 features
(dimensions).
Would you like me to help with reducing these dimensions efficiently? 🚀
Yes! In this context, a dimension is considered a column in the dataset.
data = np.random.rand(1000, 512)
is a
matrix (2D NumPy array)
with:
Each row (sample) is represented by 512 numerical values, meaning each data point exists in a 512-dimensional space.
Row (Sample) | Columns (Dimensions/Features) |
---|---|
Sample 1 | [0.15, 0.89, 0.47, ..., 0.33] (512D) |
Sample 2 | [0.78, 0.56, 0.12, ..., 0.44] (512D) |
Sample 3 | [0.67, 0.21, 0.76, ..., 0.59] (512D) |
Each column (dimension) represents a feature of the data, which could be:
📌 Checking Dimensions in Python
pythonprint(f"Shape of data: {data.shape}") print(f"Number of dimensions: {data.shape[1]}")
✔ Output:
Shape of data: (1000, 512) Number of dimensions: 512
✅
Yes, in this context, a dimension is the same as a
column.
✅ Each
row
represents a
data point
in a
512-dimensional space.
✅ Each
column (dimension)
represents an
individual feature
describing the data.
Would you like help visualizing high-dimensional data using PCA? 🚀
I see the confusion! 512 dimensions in this context does NOT mean 512 nested arrays. Instead, it means each row (data point) has 512 numerical values (features), each stored as a column in a 2D array.
When we say "512 dimensions", we mean that each row (sample) has 512 values, representing its position in a 512-dimensional space.
📌
Example:
data = np.random.rand(3, 5)
(A small dataset)
pythonimport numpy as np data = np.random.rand(3, 5) # 3 samples, 5 dimensions each print(data)
✔ Output (Example)
[[0.15 0.89 0.47 0.62 0.33] # 1st row (1st sample, 5D) [0.78 0.56 0.12 0.91 0.44] # 2nd row (2nd sample, 5D) [0.67 0.21 0.76 0.35 0.59]] # 3rd row (3rd sample, 5D)
You were thinking "512 dimensions" means each data point contains 512 nested arrays (which is incorrect). That would look something like:
pythondata = [[ [...], [...], ..., [...]] ] # 512 nested arrays inside each row
That structure is not how vector data is represented in machine learning or vector databases.
If you had 512 nested arrays, the shape would be (1000, 512, something_else), meaning each data point contains 512 individual arrays, each with further values.
📌 Example of a True Nested Array (Shape: 1000 × 512 × 3)
pythonnested_data = np.random.rand(1000, 512, 3) # Each data point has 512 sub-arrays, each with 3 values print(nested_data.shape) # Output: (1000, 512, 3)
👎 This is NOT how normal vector embeddings work in machine learning.
✅ "512 dimensions" just means that each row has
512 values.
There are
no nested arrays inside each row. It’s just a
2D NumPy array (matrix) where each row is a point
in a 512-dimensional space.
Would you like help visualizing high-dimensional data in 2D using PCA? 🚀