Compare matrices using PCA similarity factor

## Arguments

- x
Matrix with sample in column and features in row

- y
Matrix is compared to x.

- dim
number of retained dimensions in the comparison. Defaults to all.

## Value

Ratio of projected variance to total variance

## References

Singhal, A. and Seborg, D. E. (2005), Clustering multivariate time-series data. J. Chemometrics, 19: 427-438. doi: 10.1002/cem.945

## Author

Edgar Zanella Alvarenga