MATLAB:使用列表访问多维数组的元素 [英] MATLAB: Accessing an element of a multidimensional array with a list

问题描述

我有一个d维数组 A 和长度为d的向量 inds .我想通过 inds 访问 A 的值.

I have a d-dimensional array, A, and vector inds with length equal to d. I would like to access the value of A at inds.

理想情况下，我会做类似 A(* inds)的事情(借用Python的拆包语法).我不确定如何在MATLAB中执行此操作.

Ideally, I'd do something like A(*inds) (borrowing the unpacking syntax from Python). I'm not sure how to do this in MATLAB.

如果我执行 A(inds)，我实际上会从 A 中获得d个单独的值，这不是我想要的.我想要的是将 inds 的元素i用作函数调用 A ()中的第i个参数.

If I do A(inds) I actually get d separate values from A, which is not what I want. What I want is for element i of inds to be the ith parameter in the function call A().

推荐答案

一种解决方案是创建 NUM2CELL 将其转换为单元格数组来实现，然后在索引A时使用{:}语法:

One solution is to create a comma-separated list out of your vector of subscripted indices inds. You can do this by converting it to a cell array using NUM2CELL, then using the {:} syntax when indexing A:

inds = num2cell(inds);
value = A(inds{:});

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