app.py

import streamlit as st
import numpy as np
from sklearn.neighbors import KNeighborsClassifier
import matplotlib.pyplot as plt

def get_user_data_train():
    data_points = []
    labels = []

    for i in range(5):
        x = st.number_input(f"Enter x-coordinate for data point {i + 1}:")
        y = st.number_input(f"Enter y-coordinate for data point {i + 1}:")
        label = st.text_input(f"Enter label for data point {i + 1}:")

        data_points.append([x, y])
        labels.append(label)

    return np.array(data_points), np.array(labels)
    
def get_user_data_test():
    data_points = []

    for i in range(1, 2, 1):
        x = st.number_input(f"Enter x-coordinate for test data point {i + 1}:")
        y = st.number_input(f"Enter y-coordinate for test data point {i + 1}:")
        
        data_points.append([x, y])

    return np.array(data_points)

def knn_classification(X_train, y_train, X_test, k_value):
    knn_classifier = KNeighborsClassifier(n_neighbors=k_value)
    knn_classifier.fit(X_train, y_train)
    predictions = knn_classifier.predict(X_test)
    return predictions

def plot_training_and_test_data(X_train, y_train, X_test, predictions):
    unique_labels = np.unique(y_train)

    # Plot training data
    for label in unique_labels:
        indices = np.where(y_train == label)
        plt.scatter(X_train[indices, 0], X_train[indices, 1], label=f'Training ({label})')

    # Plot test data with predicted labels
    plt.scatter(X_test[:, 0], X_test[:, 1], label=f'Test (Predicted Labels)', marker='x', c=predictions)

    plt.xlabel('X-coordinate')
    plt.ylabel('Y-coordinate')
    plt.title('Training and Test Data with Predicted Labels')
    plt.legend()
    st.pyplot()

def main():
    st.title("K-Nearest Neighbor Classification App")

    # Get user-defined data train
    X_train, y_train = get_user_data_train()

    # Choose the value of k
    k_value = st.slider("Choose the value of k for k-nearest neighbors:", min_value=1, max_value=10, value=3)
    
    # Get user-defined data test
    X_test = get_user_data_test()
    
    # Perform k-nearest neighbor classification
    predictions = knn_classification(X_train, y_train, X_test, k_value)

    # Plot training and test data
    plot_training_and_test_data(X_train, y_train, X_test, predictions)

    # Display results
    st.subheader("Results:")
    st.write("User-defined Data Points for Testing:")
    st.write(X_test)
    st.write(f"\nK-Nearest Neighbor Classification (k={k_value}):")
    st.write("Predicted Labels:")
    st.write(predictions)

if __name__ == "__main__":
    main()