Regression in Numpy and Scikit-learn: Solutions Exercises 1 and 2

In exercise 1 we implement linear regression in Numpy. In exercise 2 we investigate how number of features affects linear regression using Scikit-learn. The notebook can be found here: https://github.com/MachineLearningBiomedicalApplications/notebooks/blob/c7ba06f021e8f95c8a8e18e877aa81dde89ee28d/Chapter%203%20-%20Regression/Notebooks/3.1.%20Multivariate%20Linear%20Regression.ipynb