[Numpy] 연산

산술연산

 

import numpy as np

array1 = np.arange(10)
array2 = np.arange(10, 20)


print(array1)
print(array2)
print(array1 * 2)
print(array2 / 2)
print(array1 + array2)

 

 

 

불린연산

import numpy as np

array1 = np.array([2,3,5,7,11,13,17])

print(array1 > 4)
print(array1 % 2 == 0 )


# [False False  True  True  True  True  True]
# [ True False False False False False False]

 

 

np.where 함수

booleans = np.array([ True, True, False, True, True, False, True])
print(np.where(booleans))

# (array([0, 1, 3, 4, 6]),)

 

 

filter 사용

filter = np.where(array1 > 4)
print(filter)
# (array([2, 3, 4, 5, 6]),)


print(array1[filter])
# [ 5  7 11 13 17]

 

 

 

 

TEST

import numpy as np

revenue_in_yen = [
    300000, 340000, 320000, 360000, 
    440000, 140000, 180000, 340000, 
    330000, 290000, 280000, 380000, 
    170000, 140000, 230000, 390000, 
    400000, 350000, 380000, 150000, 
    110000, 240000, 380000, 380000, 
    340000, 420000, 150000, 130000, 
    360000, 320000, 250000
]

# 여기에 코드를 작성하세요
yen_array = np.array(revenue_in_yen)
filter = np.where( yen_array <= 200000) 
bad_days_revenue = yen_array[filter]

# 테스트 코드
bad_days_revenue