import numpy as np
import time
data = np.random.rand(110000000)
print(data)
# List
start = time.time()
mean_list = sum(data) / len(data)
print(time.time() - start)
# Numpy
start = time.time()
mean_np = np.mean(data)
print(time.time() - start)
mean_list
mean_np
# syntax
# arr = np.array()
# arr
# 0D (zero dimensional)
arr0 = np.array(1)
# 1D (one dimensional)
arr = np.array([1, 2, 3, 4, 5])
arr
# 2D (2 dimensional)
arr2 = np.array([[1, 2, 3, 4, 5], [6, 7, 8, 9, 10]])
arr2
# 3D (3 dimensional)
arr3 = np.array(
[
[
[1, 2, 3],
[4, 5, 6]
],
[
[7, 8, 9],
[10, 11, 12]
]
]
)
arr3
type(arr3)
# 0D (zero dimensional)
arr0 = np.array(1)
arr0.ndim
# 1D (one dimensional)
arr = np.array([1, 2, 3, 4, 5])
arr
arr.ndim
# 2D (2 dimensional)
arr2 = np.array([[1, 2, 3, 4, 5], [6, 7, 8, 9, 10]])
arr2.ndim
# 3D (3 dimensional)
arr3 = np.array(
[
[
[1, 2, 3],
[4, 5, 6]
],
[
[7, 8, 9],
[10, 11, 12]
]
]
)
arr3.ndim
arr10 = np.array([1, 2, 3, 4], ndmin=10)
arr10.ndim
arr10
arr3.shape
arr10.shape
arr2.shape
arr3.dtype
arrs = np.array(['a', 'b'])
arrs.dtype
arr1 = np.array([1, 2, 3], dtype=np.float64)
arr1.dtype
arr1.astype(np.int32)
arr1.size
arr2.size
arr2
#### 1 for the column
# 0 for the row
np.size(arr2, 1)
arr2.itemsize
arr2.nbytes
aranged_array = np.arange(10)
aranged_array
aranged_array2 = np.arange(2, 10) ## craete a 1D array with start with 2 and end with 9
aranged_array2
aranged_array3 = np.arange(2, 10, 2) # create 1D ndarray with start with 2 and end with 9 and increment 2
aranged_array3
aranged_array4 = np.arange(1, 2, 0.1)
aranged_array4
## zeros(shape, dtype)
zero_arr = np.zeros(2, dtype=int)
zero_arr
zero_arr = np.zeros([3, 5], dtype=int)
zero_arr
arr = np.array([[1, 2, 3], [4, 5, 6]])
arr.ndim
arr0 = np.zeros((3, 3))
arr0
arr0 = np.zeros(10)
arr0
arr0 = np.zeros([2, 3, 4])
arr0
arr1 = np.ones([3, 4])
arr1
arre = np.empty([3, 4])
arre
arr = np.full([3, 4], 10)
arr
arre = np.eye(3)
arre
arrd = np.diag([1, 2, 3, 4])
arrd
arr = np.linspace(0, 10, 20)
arr
arrr = np.random.rand(10)
arrr
arrr = np.random.randint(15, 25, size=(2, 3))
arrr
arrr = np.arange(1, 12, 2)
arrr
arr1 = np.array([1, 2, 3, 4, 5, 6, 7, 8, 9])
arr2 = np.array([[1, 2, 3, 4], [5, 6, 7, 8, ], [1, 3, 5, 7]])
arr2
arr1[4]
arr1[-1]
# arr2[row,column]
arr2[1, 3]
arr2[1, 3] = 20
arr2
arr2
arr2[1:]
#Quiz
arr = np.linspace(10, 500, 12).reshape([3, 4])
arr
arr = np.random.rand(63).reshape([7, 9])
arr