给定（固定）元素的索引时创建一个numpy数组

Question

I have a numpy array of indexes eg [1,3,12] . I want to create another array from this such that at these indexes, I get a non-zero elements eg 1. So in this case, with input [1,3,12] , I should get [0,1,0,1,0,0,0,0,0,0,0,0,1] . I can do it in a for loop, is there a short numpy function to achieve this?

Answer 1

With numpy you can index with lists directly:

a = [1,3,12]
vector = numpy.zeros(shape=max(a) + 1)
vector[a] = 1