import matplotlib.pyplot as plt
import numpy as np
import csv
import math

def read_csv(filename):
    data = list()
    header = None
    with open(filename, "r") as file:
        reader = csv.reader(file)
        header = next(reader, None)
        print(header)
        for row in reader:
            data.append([float(d) for d in row])

    return header, data

def main(filename):
    header, data = read_csv(filename)

    x = [d[0] for d in data]
    y = dict()
    for h in range(1, len(header)):
        y[header[h]] = list()

    for d in data:
        for idx in range(0, len(d)-1):
            y[header[idx+1]].append(d[idx+1])

    min_x = min(x)
    max_x = max(x)

    min_x_tick_power = math.floor(math.log10(min_x))
    max_x_tick_power = math.ceil(math.log10(max_x))

    xticks = [10**p for p in range(min_x_tick_power, max_x_tick_power)]

    headers = list()
    for key,value in y.items():
        plt.plot(x, value)
        headers.append(key)

    plt.legend(["acc={}".format(h) for h in headers])

    plt.xscale("log")
    plt.grid(True)
    plt.xlabel("Input to sqrt()")
    plt.ylabel("Relative Error")
    #plt.xticks(xticks)
    plt.title("Relative error of sqrt()")
    plt.show()


if __name__ == "__main__":
    main("exercise_1_7_data.csv")