9.1
# -*- coding: utf-8 -*-
"""
Created on Mon May 21 20:55:33 2018
@author: 12046
"""
import numpy as np
from scipy.linalg import toeplitz
def f(A,B,mylambda):
size=B.shape[1]
print(A.dot(B-mylambda*np.eye(size)))
n,m=200,500
A=np.random.normal(size=(n,m))
B=toeplitz(range(1,m+1),range(1,m+1))
print(A+A)
print(A.dot(A.T))
print(A.T.dot(A))
print(A.dot(B))
f(A,B,0.5)
9.2
# -*- coding: utf-8 -*-
"""
Created on Mon May 21 20:55:33 2018
@author: 12046
"""
import numpy as np
from scipy.linalg import toeplitz
def f(A,B,mylambda):
size=B.shape[1]
print(A.dot(B-mylambda*np.eye(size)))
n,m=200,500
A=np.random.normal(size=(n,m))
B=toeplitz(range(1,m+1),range(1,m+1))
b=np.arange(1,m+1)
x=np.linalg.solve(B,b)
print(x)
9.3
# -*- coding: utf-8 -*-
"""
Created on Mon May 21 20:55:33 2018
@author: 12046
"""
import numpy as np
from scipy.linalg import toeplitz
def f(A,B,mylambda):
size=B.shape[1]
print(A.dot(B-mylambda*np.eye(size)))
n,m=200,500
A=np.random.normal(size=(n,m))
B=toeplitz(range(1,m+1),range(1,m+1))
print(A)
print(np.linalg.norm(A))
print(B)
print(np.linalg.norm(B,ord=np.inf))
#largest
print(np.linalg.norm(B,ord=2))
#smallest
print(np.linalg.norm(B,ord=-2))
9.4
# -*- coding: utf-8 -*-
"""
Created on Mon May 21 20:55:33 2018
@author: 12046
"""
import numpy as np
from scipy.linalg import toeplitz
import time
def f(A,B,mylambda):
size=B.shape[1]
print(A.dot(B-mylambda*np.eye(size)))
n,m=200,500
A=np.random.normal(size=(n,m))
B=toeplitz(range(1,m+1),range(1,m+1))
Z=np.random.normal(size=(n,n))
t1=time.clock()
eigenvalue,eigenvector=np.linalg.eig(Z)
t2=time.clock()
print(t2-t1)
9.5
# -*- coding: utf-8 -*-
"""
Created on Mon May 21 20:55:33 2018
@author: 12046
"""
import numpy as np
from scipy.linalg import toeplitz
import time
n=200
p=np.random.random(1)
C=np.random.binomial(1,p,(n,n))
print(np.linalg.norm(C,ord=2))
print(n*p)
9.6
# -*- coding: utf-8 -*-
"""
Created on Mon May 21 20:55:33 2018
@author: 12046
"""
import numpy as np
from scipy.linalg import toeplitz
import time
n=200
A=np.random.normal(size=n)
z=np.random.random(1)
print(A)
print(z)
close_index=(np.abs(A-z)).argmin()
close_value=A[close_index]
print(close_value)