diff --git a/machine_learning/dbscan.py b/machine_learning/dbscan.py index 3e044d8f6..566f8e217 100644 --- a/machine_learning/dbscan.py +++ b/machine_learning/dbscan.py @@ -2,8 +2,10 @@ import pandas as pd import math import matplotlib.pyplot as plt from typing import Dict, List + + class dbscan: - ''' + """ DBSCAN Algorithm : Density-Based Spatial Clustering Of Applications With Noise Refer this website for more details : https://en.wikipedia.org/wiki/DBSCAN @@ -21,9 +23,10 @@ class dbscan: obj = dbscan.dbscan(minPts, radius, file) obj.print_dbscan() obj.plot_dbscan() - ''' - def __init__(self, minPts : int, radius : int, file : str) -> None: - ''' + """ + + def __init__(self, minPts: int, radius: int, file: str) -> None: + """ Constructor Attributes: @@ -48,13 +51,14 @@ class dbscan: 6 | 4 7 | 3 ----- - ''' + """ self.minPts = minPts self.radius = radius self.file = file self.dict1 = self.perform_dbscan() + def perform_dbscan(self) -> Dict[int, List[int]]: - ''' + """ Parameters: ----------- None @@ -62,7 +66,7 @@ class dbscan: Return: -------- Dictionary with points and the list of points that lie in its radius - ''' + """ data = pd.read_csv(self.file) minPts = self.minPts @@ -71,50 +75,75 @@ class dbscan: dict1 = {} for i in range(len(data)): for j in range(len(data)): - dist = math.sqrt(pow(data['x'][j] - data['x'][i],2) + pow(data['y'][j] - data['y'][i],2)) + dist = math.sqrt( + pow(data["x"][j] - data["x"][i], 2) + + pow(data["y"][j] - data["y"][i], 2) + ) if dist < e: - if i+1 in dict1: - dict1[i+1].append(j+1) + if i + 1 in dict1: + dict1[i + 1].append(j + 1) else: - dict1[i+1] = [j+1,] + dict1[i + 1] = [ + j + 1, + ] return dict1 + def print_dbscan(self) -> None: - ''' + """ Outputs: -------- Prints each point and if it is a core or a noise (w/ border) - ''' + """ for i in self.dict1: - print(i," ",self.dict1[i], end=' ---> ') + print(i, " ", self.dict1[i], end=" ---> ") if len(self.dict1[i]) >= self.minPts: print("Core") else: for j in self.dict1: - if i != j and len(self.dict1[j]) >= self.minPts and i in self.dict1[j]: + if ( + i != j + and len(self.dict1[j]) >= self.minPts + and i in self.dict1[j] + ): print("Noise ---> Border") break else: print("Noise") + def plot_dbscan(self) -> None: - ''' + """ Output: ------- A matplotlib plot that show points as core and noise along with the circle that lie within it. - ''' + """ data = pd.read_csv(self.file) e = self.radius for i in self.dict1: if len(self.dict1[i]) >= self.minPts: - plt.scatter(data['x'][i-1], data['y'][i-1], color='red') - circle = plt.Circle((data['x'][i-1], data['y'][i-1]), e, color='blue', fill=False) + plt.scatter(data["x"][i - 1], data["y"][i - 1], color="red") + circle = plt.Circle( + (data["x"][i - 1], data["y"][i - 1]), e, color="blue", fill=False + ) plt.gca().add_artist(circle) - plt.text(data['x'][i-1], data['y'][i-1], 'P'+str(i), ha='center', va='bottom') + plt.text( + data["x"][i - 1], + data["y"][i - 1], + "P" + str(i), + ha="center", + va="bottom", + ) else: - plt.scatter(data['x'][i-1], data['y'][i-1], color='green') - plt.text(data['x'][i-1], data['y'][i-1], 'P'+str(i), ha='center', va='bottom') - plt.xlabel('X') - plt.ylabel('Y') - plt.title('DBSCAN Clustering') - plt.legend(['Core','Noise']) + plt.scatter(data["x"][i - 1], data["y"][i - 1], color="green") + plt.text( + data["x"][i - 1], + data["y"][i - 1], + "P" + str(i), + ha="center", + va="bottom", + ) + plt.xlabel("X") + plt.ylabel("Y") + plt.title("DBSCAN Clustering") + plt.legend(["Core", "Noise"]) plt.show()