How to use Nearest Neighbours for Classification in Python

How to use Nearest Neighbours for Classification in Python

Nearest Neighbors is a popular method of statistical analysis that can be used to predict a categorical variable based on a set of input variables. In this article, we will go over the basics of how to use Nearest Neighbors for classification in Python.

First, we need to import the necessary libraries such as Numpy and Pandas, which will help us handle our data. Next, we will import the KNeighborsClassifier class from the sklearn.neighbors library, which will be used to create our model.

Once we have our libraries and classes imported, we can start creating our model. To do this, we will first need to load our data into a Pandas dataframe. We can do this by using the read_csv function, which will allow us to read in data from a CSV file.

Once our data is loaded, we will need to split it into training and testing sets. This is important because it allows us to test the accuracy of our model on unseen data. We can do this using the train_test_split function, which will randomly split our data into training and testing sets.

Now that our data is ready, we can create our model. We do this by instantiating the KNeighborsClassifier class and then fitting it to our training data using the fit method. Once the model is trained, we can use it to make predictions on our testing data using the predict method.

To check the accuracy of our model, we can use different metrics such as accuracy score, precision, recall, and f1-score. The higher the accuracy score, the better our model is at classifying the data.

Lastly, we need to optimise our model. One way to do this is by tuning the model’s parameters. The most important parameter is the number of nearest neighbours, which controls how many data points will be used to make the prediction. We can use a grid search to find the best number of nearest neighbours for our data.

 

In this Learn through Codes example, you will learn: How to use Nearest Neighbours for Classification in Python.



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