# download the software
import urllib

urllib.urlretrieve('https://github.com/sods/ods/archive/master.zip', 'master.zip')

# unzip the software
import zipfile
zip = zipfile.ZipFile('./master.zip', 'r')
for name in zip.namelist():
    zip.extract(name, '.')

# add the module location to the python path.    
import sys
sys.path.append("./ods-master/") 

import numpy as np
import pods
data = pods.datasets.olympic_marathon_men()
x = data['X']
y = data['Y']

%matplotlib inline
import pylab as plt
plt.plot(x, y, 'rx')

#### Question 1 Answer Code
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# Make sure your code has run and the answer is correct *before* submitting your notebook for marking.


#### Question 2 Answer Code
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# select indices of data to 'hold out'
indices_hold_out = np.flatnonzero(x>1980)

# Create a training set
x_train = np.delete(x, indices_hold_out, axis=0)
y_train = np.delete(y, indices_hold_out, axis=0)

# Create a hold out set
x_valid = np.take(x, indices_hold_out, axis=0)
y_valid = np.take(y, indices_hold_out, axis=0)

#### Question 3 Answer Code
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#### Question 4 Answer Code
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train_err

#### Question 5 Answer Code
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#### Question 6 Answer Code
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