我想在Python中找到一种快速的方法(没有for循环)来分配数组的重新索引索引.这是使用for循环的期望结果:
import numpy as np
a=np.arange(9, dtype=np.float64).reshape((3,3))
# The array indices: [2,3,4] are identical.
Px = np.uint64(np.array([0,1,1,1,2]))
Py = np.uint64(np.array([0,0,0,0,0]))
# The array to be added at the array indices (may also contain random numbers).
x = np.array([.1,.1,.1,.1,.1])
for m in np.arange(len(x)):
a[Px[m]][Py[m]] += x
print a
%[[ 0.1 1. 2.]
%[ 3.3 4. 5.]
%[ 6.1 7. 8.]]
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当我尝试添加x到a索引时,Px,Py我显然得不到相同的结果(3.3对3.1):
a[Px,Py] += x
print a
%[[ 0.1 1. 2.]
%[ 3.1 4. 5.]
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