#!/usr/bin/python3
import matplotlib
matplotlib.use('Agg') #Non interactive backend
import matplotlib.pyplot as plt
import numpy as np

def main():
    x=np.linspace(0,2*np.pi,100)
    fig,axs=plt.subplots(2,2, figsize=(10,8))
    axs[0,0].plot(x,np.sin(x),'b-')
    axs[0,0].set_title('sin(x)')
    axs[0,1].plot(x,np.cos(x),'g-')
    axs[0,1].set_title('cos(x)')
    axs[1,0].plot(x,np.tan(x),'r-')
    axs[1,0].set_title('tan(x)')
    axs[1,1].plot(x,np.exp(x),'k-')
    axs[1,1].set_title('exp(x)')
    plt.tight_layout()
    plt.savefig('fig5.png',dpi=300,transparent=True)

if __name__=="__main__":
    main()