Efficient LSV Approximation for Large Matrices | Conjugate Gradient Method Guide

  • Context: Graduate 
  • Thread starter Thread starter onako
  • Start date Start date
  • Tags Tags
    Approximation
Click For Summary
SUMMARY

The discussion focuses on efficiently approximating the left singular vectors (LSVs) and the corresponding largest singular values of a large matrix G (with dimensions nxk, where n>>k). The Conjugate Gradient method is suggested as a potential approach to achieve this approximation. Truncated Singular Value Decomposition (SVD) is identified as a viable solution, although the original poster expresses a need for practical implementation examples. The requirement is specifically for two LSVectors and their largest two singular values.

PREREQUISITES
  • Understanding of Singular Value Decomposition (SVD)
  • Familiarity with the Conjugate Gradient method
  • Knowledge of matrix dimensions and properties (specifically nxk matrices)
  • Basic programming skills for implementing numerical methods
NEXT STEPS
  • Research Truncated SVD implementation in Python using libraries like NumPy or SciPy
  • Explore examples of the Conjugate Gradient method applied to matrix approximations
  • Study the mathematical foundations of left singular vectors and their significance
  • Investigate optimization techniques for handling large matrices in numerical computations
USEFUL FOR

Data scientists, machine learning practitioners, and researchers working with large matrices who need efficient methods for singular value approximations and matrix decompositions.

onako
Messages
86
Reaction score
0
For certain computations I need a quick approximation of the left singular vector of a matrix G( nxk ; n>k ). Also, the corresponding singular value would be needed. Perhaps after approximating the singular value I could use the Conjugate Gradient method to obtain the approximation of the left singular vector. Any idea on how to achieve this would be very welcome.
Note that for matrix G, n which is the number of rows, is very large ( n>>k).
Thanks
 
Physics news on Phys.org
I read that Truncated SVD might be one of the solution for my problem:
http://en.wikipedia.org/wiki/Singular_value_decomposition#Truncated_SVD
Unfortunately, there are no examples I might use in order to implement this method.
Note that there is a need for Left singular vector (if it is not necessary to compute the Right singular vector) only
and the largest singular value (to be precise I need 2 LSVectors and the corresponding largest 2 singular values).
Any other suggestion on how to achieve this, or an example on how to perform Truncated SVD is very welcome.
 
Anyone?
 

Similar threads

  • · Replies 15 ·
Replies
15
Views
5K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 14 ·
Replies
14
Views
3K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 17 ·
Replies
17
Views
7K
  • · Replies 2 ·
Replies
2
Views
2K