





'''simple docstring'''




from math import sqrt

import numpy as np
from sympy import symbols

# Coefficient
# Speed of light (m/s)
a__					:			List[str]          =     2_9979_2458

# Symbols
a__      ,       a__      ,       a__      ,       a__					:			List[Any]          =     symbols('''ct x y z''')




def 						__lowerCamelCase			(	UpperCAmelCase_							)   ->float:
	if velocity > c:
		raise ValueError('Speed must not exceed light speed 299,792,458 [m/s]!'							)
	elif velocity < 1:
		# Usually the speed should be much higher than 1 (c order of magnitude)
		raise ValueError('Speed must be greater than or equal to 1!'							)

	return velocity / c




def 						__lowerCamelCase			(	UpperCAmelCase_							)   ->float:
	return 1 / sqrt(1 - beta(UpperCAmelCase_							) ** 2							)




def 						__lowerCamelCase			(	UpperCAmelCase_							)   ->np.ndarray:
	return np.array(
	    [
	        [gamma(UpperCAmelCase_							), -gamma(UpperCAmelCase_							) * beta(UpperCAmelCase_							), 0, 0],
	        [-gamma(UpperCAmelCase_							) * beta(UpperCAmelCase_							), gamma(UpperCAmelCase_							), 0, 0],
	        [0, 0, 1, 0],
	        [0, 0, 0, 1],
	    ]							)




def 						__lowerCamelCase			(	UpperCAmelCase_					,				UpperCAmelCase_ = None							)   ->np.ndarray:
	# Ensure event is not empty
	if event is None:
		snake_case__	       =   np.array([ct, x, y, z]							)  # Symbolic four vector
	else:
		event[0] *= c  # x0 is ct (speed of light * time)

	return transformation_matrix(UpperCAmelCase_							) @ event


if __name__ == "__main__":
			import doctest

			doctest.testmod()

			# Example of symbolic vector:
			a__					:			Dict          =     transform(2997_9245)
			print('''Example of four vector: ''')
			print(f"""ct' = {four_vector[0]}""")
			print(f"""x' = {four_vector[1]}""")
			print(f"""y' = {four_vector[2]}""")
			print(f"""z' = {four_vector[3]}""")

			# Substitute symbols with numerical values
			a__					:			List[str]          =     {ct: c, x: 1, y: 1, z: 1}
			a__					:			List[str]          =     [four_vector[i].subs(sub_dict) for i in range(4)]

			print(f"""\n{numerical_vector}""")










'''simple docstring'''




import requests
from bsa import BeautifulSoup




def 						__lowerCamelCase			(	UpperCAmelCase_					,				UpperCAmelCase_							)   ->str:
	snake_case__	       =   BeautifulSoup(requests.get(UpperCAmelCase_					,				params=UpperCAmelCase_							).content					,				'html.parser'							)
	snake_case__	       =   soup.find('div'					,				attrs={'class': 'gs_ri'}							)
	snake_case__	       =   div.find('div'					,				attrs={'class': 'gs_fl'}							).find_all('a'							)
	return anchors[2].get_text()


if __name__ == "__main__":
			a__					:			int          =     {
			    '''title''': (
			        '''Precisely geometry controlled microsupercapacitors for ultrahigh areal '''
			        '''capacitance, volumetric capacitance, and energy density'''
			    ),
			    '''journal''': '''Chem. Mater.''',
			    '''volume''': 30,
			    '''pages''': '''3979-3990''',
			    '''year''': 2018,
			    '''hl''': '''en''',
			}
			print(get_citation('''https://scholar.google.com/scholar_lookup''', params=params))



