Co occurrence Matrix

A co-occurrence matrix captures the frequencies with which pairs of words appear together in a certain context. The "context" can be defined in various ways: it might be within a fixed window of $n$ words, within the same sentence, or some other scope.

For a simple example, consider the sentences:

1. "I love to eat apples."
2. "Apples are nutritious."
3. "I love nutritious food."

A co-occurrence matrix (with a window size of 1 word) might look something like:

	I	love	to	eat	apples	are	nutritious	food
I	0	2	1	0	0	0	0	0
love	2	0	1	1	0	0	1	1
...

Each entry (i, j) in the matrix indicates how often word i appears next to word j in the corpus.

This raw co-occurrence matrix can be used for various purposes:

• Semantic Analysis: Words that frequently appear together are likely related in meaning.
• Building embeddings: Techniques like GloVe leverage co-occurrence statistics to generate word embeddings.