PCA to reduce dimensionality of feature vector

I have a feature vector of size 4096x180 ( 180 samples ). I want to reduce the dimensionality using PCA. I have looked at various codes available but not able to apply it. How do I write the code in Matlab 2014?

Answer 1

[Mohammad Haghighat]

Please check the Matlab's pca command:

https://www.mathworks.com/help/stats/pca.html

Answer 2

[Matlaber]

I just want to have a simple PCA to reduce my dimensionality of let say 400 * 5000 to 400 * 4

meaning reduce from 5000 to 4.

I am not sure where can I set the value of reduction.

coeff = pca(X)

I am trying to follow:

load hald

Then:

The dataset of ingredient is 13 * 4

coeff = pca(ingredients)    

Output:

 coeff = 4×4
   -0.0678   -0.6460    0.5673    0.5062
   -0.6785   -0.0200   -0.5440    0.4933
    0.0290    0.7553    0.4036    0.5156
    0.7309   -0.1085   -0.4684    0.4844

I am wondering can i change it to output of 13 *2 (13 x 2)