PolynomialFeatures is a useful tool in Machine learning for creating polynomial features, which are derived from the original features by taking their powers and interactions. Feature interactions can be important in capturing complex relationships between features.
Here’s an example of how to use PolynomialFeatures to create feature interactions:
In this example, we create a sample dataset with two features, and then initialize a PolynomialFeatures object with degree 2. We then transform the original features to polynomial features using the
The resulting polynomial features include the original features as well as their interactions.
Here are some different ways to create feature interactions using PolynomialFeatures:
1. Default degree:
By default, PolynomialFeatures creates polynomial features up to
degree 2, which means it includes all pairwise interactions between the input features.
Here’s an example;
2. Higher degree:
You can also specify a higher degree to create more complex feature interactions. For example, if you set
degree=3, PolynomialFeatures will include all interactions up to degree 3. This will create even more features, including cubic and higher-order terms.
3. Interaction only:
Sometimes you may want to create only the interaction terms without including the original features or their powers. In this case, you can set
include_bias=False and set the degree argument to 2 or higher.
In this case, the resulting features only include the interaction terms (x1x2), and not the original features or their powers.
These are just a few examples of how to create feature interactions using PolynomialFeatures. There are many other ways to use this tool, such as including only certain interaction terms, specifying different interaction orders for different features, and more. The key is to experiment with different settings and see what works best for your particular problem.