为矩阵的每一行设置特定列的值 [英] Set a value of a specific column for each row of a matrix

问题描述

我有一个包含m行的矩阵A，我想将每一行的特定元素设置为1.列索引因行而异，并由列向量a指定(与m值).也就是说，我要A_{i,a_i} = 1.在Matlab中有没有一种快速的方法(没有for循环)?

I have a matrix A with m rows and I'd like to set a specific element of each row equal 1. The column index varies from row to row and is specified by a column vector a (with m values). That is, I want A_{i,a_i} = 1. Is there a quick way to do this in Matlab (without a for-loop)?

推荐答案

我使用

I solved it using the sub2ind function:

A(sub2ind(size(A), 1:numel(a), a')) = 1

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