## Can we use ROC curve for decision tree?

Normally we cannot draw an ROC curve for the discrete classifiers like decision trees.

**What is ROC in decision tree?**

In doing decision tree classification problems, I have often graphed the ROC (Receiver Operating Characteristic) curve. The True Positive Rate (TPR) is on the y-axis, and the False Positive Rate (FPR) is on the x-axis. True Positive is when the lab test predicts you have the disease and you actually do have it.

**Does R have decision tree?**

R has packages which are used to create and visualize decision trees. For new set of predictor variable, we use this model to arrive at a decision on the category (yes/No, spam/not spam) of the data. The R package “party” is used to create decision trees.

### How do you code a decision tree in R?

To build your first decision tree in R example, we will proceed as follow in this Decision Tree tutorial:

- Step 1: Import the data.
- Step 2: Clean the dataset.
- Step 3: Create train/test set.
- Step 4: Build the model.
- Step 5: Make prediction.
- Step 6: Measure performance.
- Step 7: Tune the hyper-parameters.

**What is ROC machine learning?**

An ROC curve (receiver operating characteristic curve) is a graph showing the performance of a classification model at all classification thresholds.

**How does Python calculate ROC curve?**

ROC Curves and AUC in Python The AUC for the ROC can be calculated using the roc_auc_score() function. Like the roc_curve() function, the AUC function takes both the true outcomes (0,1) from the test set and the predicted probabilities for the 1 class.

## What is classification tree in R?

Decision Trees in R, Decision trees are mainly classification and regression types. Classification means Y variable is factor and regression type means Y variable is numeric. The main goal behind classification tree is to classify or predict an outcome based on a set of predictors.

**What is CV tree in R?**

The cv. tree() function reports the number of terminal nodes of each tree considered (size) as well as the corresponding error rate and the value of the cost-complexity parameter used (k, which corresponds to α in the equation we saw in lecture).

**How do you read a decision tree?**

Decision trees are very interpretable – as long as they are short. The number of terminal nodes increases quickly with depth. The more terminal nodes and the deeper the tree, the more difficult it becomes to understand the decision rules of a tree. A depth of 1 means 2 terminal nodes.

### How do you do a decision tree in regression in R?

In this example, let us predict the sepal width using the regression decision tree.

- Step 1: Install the required package.
- Step 2: Load the package.
- Step 3: Fit the model for decision tree for regression.
- Step 4: Plot the tree.
- Step 5: Print the decision tree model.
- Step 6: Predicting the sepal width.

**How ROC is calculated?**

The ROC curve is produced by calculating and plotting the true positive rate against the false positive rate for a single classifier at a variety of thresholds. For example, in logistic regression, the threshold would be the predicted probability of an observation belonging to the positive class.