numpyファンシーインデックス、ix_

Numpy Fancy Index Ix_

#coding:utf-8 import numpy as np b=np.arange(12).reshape(3,4) print(b.flat) for i in b.flat: print(i) f=b.flat b.flat=7 print(b) a=[1,2,3] b=[4,5,6] c=(a,b) print(np.ix_(a,b)) f=np.arange(12) print(f%4==0) v=np.array([[1,2,3],[4,5,6]]) print('v:',v) v[np.ix_(range(2),range(2))]=0 print(v) ''' Output: [[0 0 3] [0 0 6]] ''' v2=np.array([[1,2,3],[4,5,6]]) v2[range(2),range(2)]=0 #v[v>1]=0 print(v2) ''' Output: [[0 2 3] [4 0 6]] ''' #Change the value of the element v2=np.array([[1,2,3],[4,5,6]]) #v2[range(2),range(2)]=0 v2[(v2>1) & (v2 <5)]=0 print(v2) ''' Output: [[1 0 0] [0 5 6]] '''