# -*- coding: utf-8 -*-
"""
Created on Fri Sep 30 10:33:26 2022

@author: 102194
"""


import numpy as np
import matplotlib.pyplot as plt
from scipy import sparse as sp
from scipy.sparse import linalg as sla
from scipy import linalg as la

#a)
I = sp.eye(500)

#plt.spy(I)

N = 500

#b)

UD = sp.diags([1.,2.],[0,1],shape=(N,N))

plt.spy(UD)

#c)
TD = sp.diags([0.5,1,0.5],[-1,0,1],shape=(N,N))

#plt.spy(TD)