我有一个矩阵X
[[ 2. nan nan nan]
[ 3. 2. nan nan]
[ nan 5. 5. nan]
[ nan nan nan nan]]
和一个列表b
[-1.0, 2.0, 0.5, -2.0]
当我做X - b时,我得到:
[[ 3. nan nan nan]
[ 4. 0. nan nan]
[ nan 3. 4.5 nan]
[ nan nan nan nan]]
如果我想在列而不是行之间减去b,该怎么办?
我在找像X - b.transpose()这样的东西
[[ 3. nan
我试图在string列中提取特定的句子,并将其复制并粘贴到另一列的Nan行中
详细情况如下:
`
KEY WARNSIGN_DTL EVENT_DTL
55116 77981 Nan 1. Name: Johnson 2. Date: 09 June 2018 3. Place to be found: Wall street 4. Found in his apartment 5. Method: overdose Pentanil
56545 73565 Nan 1. Name: Hay
在python中,我们做了一些类似的事情,例如:
n = 30
A = numpy.zeros(shape=(n,n))
for i in range(0, n):
for j in range(0, n):
A[i, j] = i+j
#i+j just example of assignment
来管理一个2模糊的数组。太简单了。只需使用nest循环遍历行和列。
但我朋友告诉我为什么事情这么复杂。你能给我另一种方法来管理它吗?
他告诉我,在Mathematica中,有一些方法可以更容易地管理n点数组(我不确定)。我从来没有用过数学)
您能给我另一