Ask Ghassem - Recent questions tagged pca

Can PCA be used for supervised learning?

Tue, 18 Feb 2020 21:49:18 +0000

Can PCA be used for supervised learning???

I've seen some data scientists using PCA to transform their data for only numerical variables.

However, some other data scientists say that it is only used for unsupervised ML techniques.

How to calculate Covariance Matrix and Principal Components for PCA?

Wed, 26 Jun 2019 10:40:02 +0000

The dataset with two features $(x,y)$ is shown as follows (note $y$ in this example is the second feature, not a target value):

x	y
2.5	2.4
0.5	0.7
2.2	2.9
1.9	2.2
3.1	3.0
2.3	2.7
2.0	1.6
1.0	1.1
1.5	1.6
1.1	0.9

a) Calculate the Covariance Matrix.
b) Calculate eigenvalues and eigenvectors
c) Calculate all the PCs
d) How much percent of the total variance in the dataset is explained by each PC?

Great Video for K-means and PCA

Wed, 17 Oct 2018 13:46:54 +0000

PCA

https://www.youtube.com/watch?v=FgakZw6K1QQ

K-Means

https://www.youtube.com/watch?v=4b5d3muPQmA&index=10&list=PLblh5JKOoLUICTaGLRoHQDuF_7q2GfuJF&t=0s

x	y
2.5	2.4
0.5	0.7
2.2	2.9
1.9	2.2
3.1	3.0
2.3	2.7
2.0	1.6
1.0	1.1
1.5	1.6
1.1	0.9

x	y
2.5	2.4
0.5	0.7
2.2	2.9
1.9	2.2
3.1	3.0
2.3	2.7
2.0	1.6
1.0	1.1
1.5	1.6
1.1	0.9

x	y
2.5	2.4
0.5	0.7
2.2	2.9
1.9	2.2
3.1	3.0
2.3	2.7
2.0	1.6
1.0	1.1
1.5	1.6
1.1	0.9