## Blog Pages

Showing posts with label Matrix Creation. Show all posts
Showing posts with label Matrix Creation. Show all posts

### Solving linear mathematical equations with two variable

import numpy as np
A=np.array([[1.5,1],[3.75,4]])
B=np.array([1800,900])
x=np.linalg.solve(A,B)
print("Values of A and B variables:",x)
h=np.allclose(np.dot(A, x), B)
print("Substitution of two variables in equation to validate:",h)

### Operations on Matrices using Python program

import numpy as np
A = np.array([[4,1,7],[2,1,8],[3 ,7,1]])
B = np.array([[6,1,1],[2,1,5],[2,3,1]])
C=A.dot(B)
print("Values of First 2D Matrix\n",A)
print("Values of Second 2D Matrix\n",B)
print("---------------------------------------------")
print("Multiplication of Matrices\n",C)
print("\n")
Ainv=np.linalg.inv(A)
Binv=np.linalg.inv(B)
print("Inverse of First Matrix\n",Ainv)
print("Inverse of Second Matrix\n",Binv)
print("\n")
AI=Ainv.dot(A)
BI=Binv.dot(B)
print("Multiplication of First Matrix and their Inverse\n",AI)
print("Multiplication of Second Matrix and their Inverse\n",BI)
BD=np.linalg.det(B)
print("\n")
print("Determinant of Second Matricx:",BD)
print("\n")
BDi=np.diag(B)
print("Diagonal Elements of Second Matrix:",BDi)
SBDi=np.trace(B)
print("\n")
print("Sum of Diagonal Elements of First Matrix:",SADi)
print("Sum of Diagonal Elements of Second Matrix:",SBDi)
print("\n")
CA=np.cov(A)
CB=np.cov(B)
print("Covariance matrix of First Matrix\n",CA)
print("Covariance matrix of Second Matrix\n",CB)
print("\n")
ECA=np.linalg.eigh(CA)
ECB=np.linalg.eigh(CB)
print("First array represents eigenvalues and second array represents eigenvectors")
print("\n")
print("covariance matrix eigenvalues eigenvectors of First Matrix\n",ECA)
print("\n")
print("covariance matrix eigenvalues eigenvectors of Second Matrix\n",ECB)

### Multiplication of two Matrices

X = [[4,1,7],[2,1,8],[3 ,7,1]];
Y = [[6,8,1],[9,7,5],[2,3,1]];
result = [[0,0,0],[0,0,0],[0,0,0]];

for i in range(len(X)):
for j in range(len(Y)):
for k in range(len(Y)):
result[i][j] += X[i][k] * Y[k][j]

for r in result:
print(r)

### To count the elements in a nested list with all elements are list

a=[[3, 4, 5,8, 8 ], [5, 6, 7], [7, 8, 9]]

def count(a):
j=0
n=0
for b in a:
j=len(b)
n=n+j
return n

t= count(a)
print "No elements in the nested list are:",t