从2D到1D向量的有效转换方式 [英] effective way of transformation from 2D to 1D vector

问题描述

我想从给定的矩阵中在matlab中创建一维矢量，为此，我实现了以下算法，该算法使用平凡的方法

i want to create 1D vector in matlab from given matrix,for this i have implemented following algorithm ,which use trivial way

% create   one dimensional vector from 2D  matrix
function [x]=one_dimensional(b,m,n) 
 k=1;
 for i=1:m 
     for  t=1:n
         x(k)=b(i,t);
         k=k+1;
     end
 end
  x;
end

当我使用以下示例运行它时，似乎可以完成任务

when i run it using following example,it seems to do it's task fine

b=[2 1 3;4 2 3;1 5 4]

b =

     2     1     3
     4     2     3
     1     5     4

>> one_dimensional(b,3,3)

ans =

     2     1     3     4     2     3     1     5     4

但是通常我知道，数组不是在matlab中使用的好方法，因为它具有性能，那么将矩阵转换为行/列向量的有效方法应该是什么呢?我只是在乎性能.非常感谢

but generally i know that,arrays are not good way to use in matlab,because it's performance,so what should be effective way for transformation matrix into row/column vector?i am just care about performance.thanks very much

推荐答案

您可以使用(:)运算符...但是它适用于列而不是行，因此您需要使用' operator进行转置，例如:

You can use the (:) operator...But it works on columns not rows so you need to transpose using the 'operator before , for example:

b=b.';
b(:)'

ans=
   2     1     3     4     2     3     1     5     4

然后我再次换位以获取行输出(否则它将只以列形式显示相同的向量)

and I transposed again to get a row output (otherwise it'll the same vector only in column form)

或者，这是一个选项(可能是一个较慢的选项):

or also, this is an option (probably a slower one):

reshape(b.',1,[])

这篇关于从2D到1D向量的有效转换方式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！