This post is inspired by this tutorial, which talks about interpreting
the U and V matrices:

http://www.puffinwarellc.com/index.php/news-and-articles/articles/30-singular-value-decomposition-tutorial.html

Given a DataModel that generates preferences between all Users and all
Items, lets take two Users and three Items:
     I      I     I
U 0.5  0.2  0.1
U 0.8  0.3  0.2

What can we learn from an SVD factorization?

SVD gives 3 matrices and a scalar: U, a singular value matrix that
signifies the actual rank of the matrix, and transpose(V). For
simplicity, do the 1-dimensional factorization, which gives left and
right vectors instead of scalars. Ignoring the scaling matrix, we get
the Left and Right singular vectors.

The Left Singular Vector is: (column A x rows U1 and U2)

____A__
U1
U2

The Right Singular Vector is: (row B x columns I1, I2, and I3)

___I1___I2___I3
B

Now, the question: what do the Left and Right vectors encode? What do
column A and row B mean?

--
Lance Norskog
[email protected]

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