multvariate polynomial regression

[targos]

See:
https://github.com/mrocklin/multipolyfit
https://github.com/ahmetcecen/MultiPolyRegress-MatlabCentral
http://www.researchgate.net/publication/264425037_Multivariate_Polynomial_Regression_in_Data_Mining_Methodology_Problems_and_Solutions

[andcastillo]

So this issue is solved by solving #7. I'm on it