# Convert a polynomial to a Chebyshev series in Python

To convert a polynomial to a Chebyshev series, use the chebyshev.poly2cheb() method in Python Numpy. Convert an array representing the coefficients of a polynomial ordered from lowest degree to highest, to an array of the coefficients of the equivalent Chebyshev series, ordered from lowest to highest degree. The method returns a 1-D array containing the coefficients of the equivalent Chebyshev series. The parameter c, is a 1-D array containing the polynomial coefficients

## Steps

At first, import the required library −

import numpy as np
from numpy import polynomial as P

Create an array using the numpy.array() method −

c = np.array([1, 2, 3, 4, 5])

Display the array −

print("Our Array...\n",c)

Check the Dimensions −

print("\nDimensions of our Array...\n",c.ndim)

Get the Datatype −

print("\nDatatype of our Array object...\n",c.dtype)

Get the Shape −

print("\nShape of our Array object...\n",c.shape)

To convert a polynomial to a Chebyshev series, use the chebyshev.poly2cheb() method in Python Numpy −

print("\nResult (polynomial to chebyshev)...\n",P.chebyshev.poly2cheb(c))

## Example

import numpy as np
from numpy import polynomial as P

# Create an array using the numpy.array() method
c = np.array([1, 2, 3, 4, 5])

# Display the array
print("Our Array...\n",c)

# Check the Dimensions
print("\nDimensions of our Array...\n",c.ndim)

# Get the Datatype
print("\nDatatype of our Array object...\n",c.dtype)

# Get the Shape
print("\nShape of our Array object...\n",c.shape)

# To convert a polynomial to a Chebyshev series, use the chebyshev.poly2cheb() method in Python Numpy
print("\nResult (polynomial to chebyshev)...\n",P.chebyshev.poly2cheb(c))

## Output

Our Array...
[1 2 3 4 5]

Dimensions of our Array...
1

Datatype of our Array object...
int64

Shape of our Array object...
(5,)

Result (polynomial to chebyshev)...
[4.375 5. 4. 1. 0.625]

Updated on: 01-Mar-2022

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