## 22 may. 2017

### Mosaic 7.12 is now available on our Europe server

Mosaic version 7.12 is now available on our Europe server.
Once you try to connect, you should be asked to automatically download and install the new client.
User accounts, passwords remain the same.

Ports used for NOVA:

Configure correctly the ports with your IT for a successful synchonization.

## 7 may. 2017

### Easy way to check the eigen values with the T (scores) matrix

Other interesting Matrix multiplication is the product of the score matrix T by it´s transpose in this way:

Tt%*%T

This product give us a square matrix (a.a), being “a” the number of loadings or PCs chosen, and the diagonal has the eigenvalues which are related to the quantity of explained variance for every loading.

If we plot the diagonal we can see how the eigenvalue decrease by every loading. This plot can help us to decide how many loadings or PCs to choose.

## 6 may. 2017

### Checking the orthogonality of P (loadings) matrix

One of the values we got in the script of the post:"Tutorials with Resemble (Part 3 - orthoProjection) " was the loadings matrix (X.loadings), or what we called usually in this blog the P matrix.

One of the characteristics of the loadings “P” matrix, when we develop the PCA, is that if we multiply it by its transpose we get the Identity Matrix “I”

P<-X.loadings

Pt<-t(X.loadings)

P%*%Pt = I

In the “I” matrix, its diagonal is “1”, and “0” values for all the rest cells indicating that all the loadings are orthogonal between them.

Exercise:
• Check it by yourself and take out the diagonal from the P matrix.
• Represent in a graphic the first loadings:
• 1 vs 2      : a plane
• 1, 2 and 3: a cube