Python学习笔记（十三）ndarray

Posted 2020-10-02

 

aArray = array([(1,2,3), (4,5,6)])
sin(aArray)
bArray = aArray.reshape(3, 2)

# 行求和 ()
aArray.sum(axis = 0)
# array([ 5, 7, 9 ])

# 列求和
aArray.sum(axis = 1)
# array([ 6, 15 ])

cArray = array([1, 3, 5])
cArray[:1]

dArray = array([2, 4, 6])
eArray = array([7, 8, 9])
where(cArray > 2, dArray, eArray)
# array([7, 4, 6]); cArray第一个值不大于2, 取eArray:7
# cArray第二值大于二，取dArray:4; cArray第三个值大于2, 取dArray:6

def fun(x, y):
return (x+1) * (y+1)

# (9, 9)是序列大小，从0开始
arr = fromfunction(fun, (9,9))