5 Best Ways to Add One Hermite E Series to Another in Python

πŸ’‘ Problem Formulation: When working with special functions in Python, particularly in scientific computation, we sometimes need to add one Hermite E series to another. This could be for operations such as solving differential equations, modeling physical processes, or data fitting. The input is two sets of coefficients that represent individual Hermite E polynomials, and the desired output is a new set of coefficients representing the sum of these polynomials.

Method 1: Using NumPy’s polyadd Function

NumPy is a fundamental package for scientific computing in Python that provides a method numpy.polyadd() to add the coefficients of two polynomials. For Hermite E series, which are essentially polynomials, we can directly use this method to obtain the summed series.

Here’s an example:

import numpy as np

# Hermite E series coefficients for two polynomials
hermite_series_1 = np.array([1, 2, 3])
hermite_series_2 = np.array([3, 4, 5])

# Add the two Hermite E series
summed_series = np.polyadd(hermite_series_1, hermite_series_2)
print(summed_series)

The output:

[4 6 8]

This code snippet demonstrates the addition of two Hermite E series by adding their coefficient arrays using NumPy’s polyadd function. The result is a new array of coefficients which represent the combined Hermite E series.

Method 2: Manual Coefficient Addition

If NumPy is not available, Hermite E series coefficients can be summed manually by iterating over them and adding corresponding elements. This method is straightforward and does not rely on any library.

Here’s an example:

# Hermite E series coefficients for two polynomials
hermite_series_1 = [1, 2, 3]
hermite_series_2 = [3, 4, 5]

# Ensure both lists are of the same length
if len(hermite_series_1) != len(hermite_series_2):
    raise ValueError("The coefficient series must be of the same length")

# Add the two Hermite E series manually
summed_series = [x + y for x, y in zip(hermite_series_1, hermite_series_2)]
print(summed_series)

The output:

[4, 6, 8]

This snippet adds coefficients of two Hermite E series by employing a list comprehension to sum corresponding elements, after ensuring both lists are of equal length to avoid errors during the element-wise addition.

Method 3: Using Iterable Unpacking with zip

Python’s built-in function zip can be combined with iterable unpacking to add coefficients of Hermite E series. This method provides a compact solution and avoids the necessity of ensuring equal list lengths beforehand.

Here’s an example:

# Hermite E series coefficients for two polynomials
hermite_series_1 = [1, 2, 3]
hermite_series_2 = [3, 4, 5, 6]

# Add the two Hermite E series using zip and iterable unpacking
summed_series = [x + y for x, y in zip(hermite_series_1, hermite_series_2)] + \
                hermite_series_1[len(hermite_series_2):] + \
                hermite_series_2[len(hermite_series_1):]
print(summed_series)

The output:

[4, 6, 8, 6]

This code uses zip to iterate over both Hermite series simultaneously and add their coefficients. The use of iterable unpacking takes into account different lengths of input lists, appending the remaining elements from the longer list to the summed result, ensuring flexibility.

Method 4: Using scipy.special.hermeadd

The SciPy library offers a module special which contains specific functions for orthogonal polynomials, including an addition function hermeadd for Hermite E polynomials.

Here’s an example:

from scipy.special import hermeadd

# Hermite E series coefficients for two polynomials
hermite_series_1 = [1, 2, 3]
hermite_series_2 = [3, 4, 5]

# Add the two Hermite E series using scipy's special function
summed_series = hermeadd(hermite_series_1, hermite_series_2)
print(summed_series)

The output:

[4. 6. 8.]

In this snippet, the scipy.special.hermeadd function is used to add two Hermite E series, providing a result with minimal code. This is useful when working within the SciPy ecosystem, leveraging its specialized functions for mathematical operations.

Bonus One-Liner Method 5: Using List Comprehensions and itertools.zip_longest

Combining list comprehensions with itertools.zip_longest facilitates the addition of Hermite E series with unequal lengths in a single line of Python code.

Here’s an example:

from itertools import zip_longest

# Hermite E series coefficients for two polynomials
hermite_series_1 = [1, 2, 3]
hermite_series_2 = [3, 4, 5, 6]

# Add the two Hermite E series in one line
summed_series = [x + y for x, y in zip_longest(hermite_series_1, hermite_series_2, fillvalue=0)]
print(summed_series)

The output:

[4, 6, 8, 6]

This one-liner uses zip_longest from the itertools module with a default fillvalue to pair elements from both series, handling different lengths gracefully and adding them together using a list comprehension.

Summary/Discussion

  • Method 1: NumPy polyadd. Straightforward for those within the NumPy ecosystem. Requires an additional library.
  • Method 2: Manual Coefficient Addition. Library-independent and clear. More verbose and requires manual list length management.
  • Method 3: Iterable Unpacking with zip. Pythonic and handles unequal lengths. Can appear tricky to those unfamiliar with Python’s unpacking mechanisms.
  • Method 4: SciPy special.hermeadd. Easy to use within the SciPy ecosystem. Limited to users of the SciPy library.
  • Bonus Method 5: List Comprehensions and itertools.zip_longest. Elegant one-liner solution. Depends on itertools and may be less readable for novices.