Intrinsic dimension M satisfies 0 ≤ M ≤ N
Image: Alice im Miniland, CC BY-SA 4.0, via Wikimedia Commons
Intrinsic dimension M satisfies 0 ≤ M ≤ N
The intrinsic dimension of a dataset is a measure of its complexity, indicating the minimal number of variables needed to represent it. This concept helps in understanding the underlying structure of data and signals.
Example
A dataset with 100 variables might have an intrinsic dimension of 10, meaning it can be effectively represented with just 10 variables.
Remember this
Understanding intrinsic dimension helps in efficient data compression and analysis, reducing computational costs and improving clarity.
Text adapted from Wikipedia, licensed under CC BY-SA 4.0.
Manifold hypothesis
High-dimensional data lies on lower-dimensional manifolds
the Johnson-Lindenstrauss lemma says
Can we shrink big data without losing important details?
Dimensionality reduction
Dimensionality reduction transforms high-dimensional data into low-dimensional space while preserving meaningful properties
cosine similarity is preferred over dot product for normalized embeddings
Why do we need a special way to measure similarity in high-dimensional spaces?
cosine similarity works better than Euclidean distance in high dimensions
Cosine similarity measures orientation, not magnitude, making it more robust to irrelevant dimensions in high-dimensional spaces
Ordinary least squares
OLS minimizes squared differences
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