# What is Regression trees

##### What are Regression Trees?

Regression Trees are a machine learning technique used to predict numerical values. Regression trees use a decision tree algorithm to form a model that predicts the outcome of a dependent variable based on one or more independent variables.

##### Why use Regression Trees?

Regression Trees are easy to understand and interpret. They are also useful to identify important variables in a dataset. Additionally, regression trees can handle non-linear relationships between variables, as well as missing data.

##### How do Regression Trees work?

Regression Trees follow a tree-like structure, with each branching node representing a decision based on the value of a predictor variable. The predictor variables are split to maximally minimize the residual sum of squares. The splits continue recursively until a stopping criterion is met, such as a minimum number of data points per leaf, a maximum depth of the tree, or a minimum improvement in the sum of squares.

Once the tree is formed, it can be used to make predictions for new data by following the corresponding branches until reaching a leaf, which contains the predicted value.

• Can handle non-linear relationships between variables.
• Easy to understand and interpret.
• Can handle missing data.
• Can identify important variables in a dataset.
• Prone to overfitting when the tree grows too deep.
• May not generalize well to new data.
• Sensitive to the order of the data.
• May not capture interactions between variables.
##### Implementing Regression Trees

There are several packages available in programming languages such as Python, R, and MATLAB, that implement Regression Trees.

In Python, the scikit-learn library provides a DecisionTreeRegressor class that can be used to train a Regression Tree. The process involves loading the data, splitting it into training and testing sets, initializing the DecisionTreeRegressor, fitting the model to the training data, and making predictions on new data.

##### Conclusion

Regression Trees are a useful machine learning technique for predicting numerical values that are easy to understand and interpret. However, they do have their limitations and can be prone to overfitting. It's important to consider the advantages and disadvantages before deciding to use Regression Trees on a particular dataset.