Matlab/Octave 1-of-K表示 [英] Matlab/Octave 1-of-K representation

问题描述

我的y的大小为5000,1(矩阵)，其中包含1到10之间的整数.我想将这些索引扩展为10的1个向量.即y包含1,2,3 ...，我希望它扩展"为:

1 0 0 0 0 0 0 0 0 0 
0 1 0 0 0 0 0 0 0 0
0 0 1 0 0 0 0 0 0 0 

做到这一点的最佳方法是什么?

我尝试过:

Y = zeros(5000,10); Y(y) = 1; 

但是没有用.

虽然它适用于矢量:

如果y = [2 5 7]和Y = zeros(1,10)，则Y(y) = [0 1 0 0 1 0 1 0 0 0].

解决方案

n=5
Y = ceil(10*rand(n,1))
Yexp = zeros(n,10);
Yexp(sub2ind(size(Yexp),1:n,Y')) = 1

另外，考虑使用稀疏算法，例如:创建指标矩阵.. >

I have a y of size 5000,1 (matrix), which contains integers between 1 and 10. I want to expand those indices into a 1-of-10 vector. I.e., y contains 1,2,3... and I want it to "expand" to:

1 0 0 0 0 0 0 0 0 0 
0 1 0 0 0 0 0 0 0 0
0 0 1 0 0 0 0 0 0 0 

What is the best way to do that?

I tried:

Y = zeros(5000,10); Y(y) = 1; 

but it didn't work.

It works for vectors though:

if y = [2 5 7], and Y = zeros(1,10), then Y(y) = [0 1 0 0 1 0 1 0 0 0].

解决方案

n=5
Y = ceil(10*rand(n,1))
Yexp = zeros(n,10);
Yexp(sub2ind(size(Yexp),1:n,Y')) = 1

Also, consider using sparse, as in: Creating Indicator Matrix.

这篇关于Matlab/Octave 1-of-K表示的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！