Fixing test set loading and plots in PS2-5 Kernelizing\ the\ Perceptron.ipynb, and fixing source code loading in various Jupyter Notebooks

[lorenzorossi7]

2 commits.

Description of the first one

In problem-sets/PS2/PS2-5 Kernelizing the Perceptron.ipynb:

1. replaced line
   test_x, test_y = util.load_csv('data/ds5_train.csv')
   with correct line
   test_x, test_y = util.load_csv('data/ds5_test.csv')

2. showing plots for the test set, as the train_perceptron function intends to do.

Description of the second one

In Jupyter notebooks, corrected all lines that import code from /src folders. For example, line

import problem_set_1.src.linear_model
is replaced by
import src.linear_model

This is the correct way to import code from /src given the folder structure used in this repository. Otherwise, the notebook fails to find the /src folder.

[lorenzorossi7]

The first commit concludes the bug fixes discussed in a previous Pull Request (now closed): #8

[maxim5]

Thanks for the contributions!

Unfortunately any small change to the notebook results in a huge unreadable diff. I'll try to review it asap.

[lorenzorossi7]

I see the large diffs. I tried to avoid this and I committed when I was only seeing the actual change that I intentionally made (as described in the comments above) in my IDE, but it seems that GitHub detects a change in the metadata of Jupyter Notebooks anyway. I don't know how to avoid this. Any suggestion is welcome. In any case, take your time and thank your for your work. When you find time, you will see that the only relevant changes are those described in my messages above. Feel free to ask for further clarifications.