Dimensional reduction by PCA
5 views (last 30 days)
Show older comments
I have an vector x whose dimension has to be reduced to 5 x 50 by PCA.
[5,500]=size(x);
while giving the no_dimns=50 I faced a problem
Warning: Target dimensionality reduced to 5.
Is it possible to reduce the dimension of matrix from 5 x 500 to 5 x 50??
0 Comments
Accepted Answer
Shashank Prasanna
on 29 Jan 2013
I think that the code expects you provide x' or x transpose where the rows are 500 and columns are 5
8 Comments
Shashank Prasanna
on 1 Feb 2013
It appears the file in your link doesn't reconstruct but just gives you the reduced scores, which means you can do:
[pc,score,latent,tsquare] = princomp(X);
red_dim = score(:,1:50);
PCARES actually reconstructs the scores back to the original basis.
More Answers (1)
Nikos Mp
on 15 Sep 2017
2 questions: 1.So we take the scores or the reconstructed data? 2.P.Component = feature ? So we choose the best PComponents?
0 Comments
See Also
Categories
Find more on Dimensionality Reduction and Feature Extraction in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!