PYTHON

newton backward interpolation python code

# Backward Difference Table Generation 

# Importing NumPy Library
import numpy as np
import sys

# Reading number of unknowns
n = int(input('Enter number of data points: '))

# Making numpy array of n & n x n size and initializing 
# to zero for storing x and y value along with differences of y
x = np.zeros((n))
y = np.zeros((n,n))


# Reading data points
print('Enter data for x and y: ')
for i in range(n):
    x[i] = float(input( 'x['+str(i)+']='))
    y[i][0] = float(input( 'y['+str(i)+']='))
    
# Generating backward difference table
for i in range(1,n):
    for j in range(n-1,i-2,-1):
        y[j][i] = y[j][i-1] - y[j-1][i-1]

        
print('
BACKWARD DIFFERENCE TABLE
');

for i in range(0,n):
    print('%0.2f' %(x[i]), end='')
    for j in range(0, i+1):
        print('	%0.2f' %(y[i][j]), end='')
    print()