# Decision tree

A decision tree is a decision support tool that uses a tree-like model of decisions and their possible consequences, including chance event outcomes, resource costs, and utility. It is one way to display an algorithm that only considers one factor at a time and allows for different options depending on the situation.

A decision tree is a graphical representation of all the possible solutions to a decision problem. The tree is made up of nodes, which represent points in the decision process, and branches, which represent the possible courses of action that can be taken from each node. The leaves of the tree represent the final outcomes of the decision process.

The decision tree can be used to determine the optimal course of action for a given decision problem. The tree is read from left to right, and the options at each node are evaluated based on the criteria set for the problem. The option with the highest value is chosen, and the process is repeated until a final decision is reached.

### What is decision tree and its steps?

A decision tree is a graph-based model that can be used for both classification and regression tasks. The model is created by Split-Apply-Combine, where the data is first split into several partitions, then a model is fit on each partition, and finally the results are combined.

The steps in creating a decision tree are:

1. Select the best attribute to split the data on. This can be done using various criteria, such as information gain or Gini impurity.

2. Split the data on the selected attribute.

3. Repeat step 1 and 2 on each partition of data.

4. When all partitions are complete, combine the results to create the final model. What is a decision tree called? A decision tree is a graphical representation of a set of decisions and their possible outcomes. It is used to help make decisions by showing all the possible options and their expected results.

### What is decision tree in ML?

A decision tree is a supervised learning algorithm that can be used for both classification and regression tasks. The goal of the algorithm is to create a model that predicts the value of a target variable based on several input variables. The decision tree algorithm works by splitting the data into smaller and smaller groups based on the values of the input variables. The algorithm then selects the group that results in the lowest cost, which is the group that contains the most accurate predictions.

### Why is decision tree used?

There are many reasons why decision trees are used, but some of the main reasons are that they are easy to interpret, easy to use, and they can handle both numerical and categorical data.

Decision trees are easy to interpret because they are essentially a flowchart of the decisions that were made to arrive at a certain conclusion. This makes them easy to understand and explain to others.

Decision trees are easy to use because they require very little data preparation. In fact, all that is usually needed is a list of the features (variables) and their corresponding values.

Decision trees can handle both numerical and categorical data. This is important because many datasets contain both types of data, and not all machine learning algorithms can handle both.

### Where is decision tree used?

Decision trees are a popular tool in data analytics and are used in a variety of tasks such as regression, classification, and feature selection.

Decision trees are constructed using a greedy algorithm that recursively splits the data into subsets based on certain criteria. The resulting tree is a white box model that can be easily interpreted by humans.

There are a few drawbacks of decision trees, such as their tendency to overfit the training data and their lack of scalability. However, these problems can be mitigated by using techniques such as pruning and ensemble learning.