# 📝 Exercise M7.03#

As with the classification metrics exercise, we will evaluate the regression metrics within a cross-validation framework to get familiar with the syntax.

We will use the Ames house prices dataset.

import pandas as pd
import numpy as np

data = ames_housing.drop(columns="SalePrice")
target = ames_housing["SalePrice"]
data = data.select_dtypes(np.number)
target /= 1000


Note

If you want a deeper overview regarding this dataset, you can refer to the Appendix - Datasets description section at the end of this MOOC.

The first step will be to create a linear regression model.

# Write your code here.


Then, use the cross_val_score to estimate the generalization performance of the model. Use a KFold cross-validation with 10 folds. Make the use of the $$R^2$$ score explicit by assigning the parameter scoring (even though it is the default score).

# Write your code here.


Then, instead of using the $$R^2$$ score, use the mean absolute error. You need to refer to the documentation for the scoring parameter.

# Write your code here.


Finally, use the cross_validate function and compute multiple scores/errors at once by passing a list of scorers to the scoring parameter. You can compute the $$R^2$$ score and the mean absolute error for instance.

# Write your code here.