题解 | 多项式特征的Phi变换

import numpy as np

def phi_transform(data: list[float], degree: int) -> list[list[float]]:
	"""
	Perform a Phi Transformation to map input features into a higher-dimensional space by generating polynomial features.

	Args:
		data (list[float]): A list of numerical values to transform.
		degree (int): The degree of the polynomial expansion.

	Returns:
		list[list[float]]: A nested list where each inner list represents the transformed features of a data point.
	"""
	if degree < 0 or not data:
		return []
	result=[]
	for row in data:
		poly_feature=[row ** power for power in range(0,degree+1)]
		poly_feature=list(map(float,poly_feature))
		result.append(poly_feature)
	return result	

if __name__ == "__main__":
    data = eval(input())
    degree = int(input())
    print(phi_transform(data, degree))