Octave/Matlab:向向量添加新元素 [英] Octave/Matlab: Adding new elements to a vector

问题描述

有一个向量 x 并且我必须添加一个元素 (newElem) .

Having a vector x and I have to add an element (newElem) .

-

x(end+1) = newElem; 

和

x = [x newElem];

?

推荐答案

x(end+1) = newElem 更健壮一些.

x = [x newElem] 仅在 x 是行向量时有效，如果它是列向量 x = [x;newElem] 应该使用.x(end+1) = newElem 但是，适用于行向量和列向量.

x = [x newElem] will only work if x is a row-vector, if it is a column vector x = [x; newElem] should be used. x(end+1) = newElem, however, works for both row- and column-vectors.

不过一般来说，应该避免增长向量.如果您经常这样做，它可能会使您的代码陷入困境.想一想:增加一个数组涉及分配新空间、复制所有内容、添加新元素和清理旧的烂摊子……如果您事先知道正确的大小，那就太浪费时间了:)

In general though, growing vectors should be avoided. If you do this a lot, it might bring your code down to a crawl. Think about it: growing an array involves allocating new space, copying everything over, adding the new element, and cleaning up the old mess...Quite a waste of time if you knew the correct size beforehand :)

这篇关于Octave/Matlab:向向量添加新元素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！