#160 Max and min using argmax and argmax in python

#160 Max and min using argmax and argmax in python

import numpy as np
import matplotlib.pyplot as plt
import os
os.chdir(r'D:\projects\wordpress\ex160') 
os.getcwd()

def main():
    N = 100
    L = 1

    def f(i, n):
        x = i * L / N
        lam = 2 * L / (n+1)
        return x * (L-x) * np.sin(2*np.pi*x/lam)

    a = np.fromfunction(f, (N+1, 5))
    min_i = a.argmin(axis=0)
    max_i = a.argmax(axis=0)
    plt.plot(a, c='k')
    plt.plot(min_i, a[min_i, np.arange(5)], 'v', c='b', markersize=8)
    plt.plot(max_i, a[max_i, np.arange(5)], '^', c='r', markersize=8)
    plt.xlabel(r'$x$')
    plt.ylabel(r'$f_n(x)$')
    plt.savefig("example160.png", dpi=100)
    plt.show()

if __name__ == '__main__':
    main()