Python script to compute regression line/curve(1-4D).

regression_line_curve.py

#! /usr/local/bin/python3.6
"""
Regression curve
"""
import random
import sys
import traceback
import numpy as np
import matplotlib.pyplot as plt


class RegressionCurve:
    def __init__(self, xs, ys):
        self.xs, self.ys = xs, ys

    def exec(self):
        """ Execution """
        try:
            self.__scatter()  # Scatter given points
            self.__plot_1()   # Plot regression line
            self.__plot_2()   # Plot regression curve(2-D)
            self.__plot_3()   # Plot regression curve(3-D)
            self.__plot_4()   # Plot regression curve(4-D)
            self.__show()     # Graph showing
        except Exception as e:
            raise

    def __scatter(self):
        """ Scatter given points """
        try:
            print("x={}\ny={}".format(self.xs, self.ys))
            plt.scatter(self.xs, self.ys, c='#cc0000', label="Points")
        except Exception as e:
            raise

    def __plot_1(self):
        """ Plot regression line """
        try:
            a, b = np.polyfit(self.xs, self.ys, 1)
            print("a={:.4f}, b={:.4f}".format(a, b))
            fs = [a * x + b for x in self.xs]
            plt.plot(self.xs, fs, label="1-D")
        except Exception as e:
            raise

    def __plot_2(self):
        """ Plot regression curve (2-D) """
        try:
            a, b, c = np.polyfit(self.xs, self.ys, 2)
            print("a={:.4f}, b={:.4f}, c={:.4f}".format(a, b, c))
            fs = [x * (x * a + b) + c for x in self.xs]
            plt.plot(self.xs, fs, label="2-D")
        except Exception as e:
            raise

    def __plot_3(self):
        """ Plot regression curve (3-D) """
        try:
            a, b, c, d = np.polyfit(self.xs, self.ys, 3)
            print("a={:.4f}, b={:.4f}, c={:.4f}, d={:.4f}".format(a, b, c, d))
            fs = [x * (x * (x * a + b) + c) + d for x in self.xs]
            plt.plot(self.xs, fs, label="3-D")
        except Exception as e:
            raise

    def __plot_4(self):
        """ Plot regression curve (4-D) """
        try:
            a, b, c, d, e = np.polyfit(self.xs, self.ys, 4)
            print("a={:.4f}, b={:.4f}, c={:.4f}, d={:.4f}, e={:.4f}"
                  .format(a, b, c, d, e))
            fs = [x * (x * (x * (x * a + b) + c) + d) + e for x in self.xs]
            plt.plot(self.xs, fs, label="4-D")
        except Exception as e:
            raise

    def __show(self):
        """ Graph showing """
        try:
            plt.title("Regression Line/Curve (1-4D)")
            plt.xlabel("x")
            plt.ylabel("y")
            plt.legend(loc=2)
            plt.grid()
            plt.show()
        except Exception as e:
            raise


if __name__ == '__main__':
    try:
        random.seed(1)
        xs = list(range(0, 50))
        ys = [random.randint(0, 1000) for _ in range(50)]
        obj = RegressionCurve(xs, ys)
        obj.exec()
    except Exception as e:
        traceback.print_exc()
        sys.exit(1)