import matplotlib.pyplot as plt
import numpy as np

analytical_func = lambda x: 1 - (1 - np.exp(-10))*x - np.exp(-10*x)

def main():
    fig, ax = plt.subplots()
    for i in range(6):
        x = []
        y = []
        x.append(0.)
        y.append(0.)
        with open(f"output/general/out_{10**(i+1)}.txt", "r") as f:
            lines = f.readlines()
            for line in lines:
                x_i, y_i = line.strip().split(",")
                x.append(float(x_i))
                y.append(float(y_i))

        x.append(1.)
        y.append(0.)

        ax.plot(x, y, label=f"n$_{{steps}} = 10^{i+1}$")

    x = np.linspace(0, 1, 1001)
    ax.plot(x, analytical_func(x), label=f"u$_{{exact}}$")
    ax.legend()
    fig.savefig("../latex/images/problem7.pdf")

if __name__ == "__main__":
    main()