Column to row vector

193 次查看（过去 30 天）
Malachi Boodoo-Joseph
评论： DGM 2025-8-31
How to extract and convert a column to a row vector so say I want to extract 5;10;9;25 how do I convert that to a row when I extract it?

请先登录，再回答此问题。

回答（2 个）

Ameer Hamza
Ameer Hamza 2020-11-8
You can use transpose()
x = [5;10;9;25];
y = x.'; % or y = transpose(x)
  2 个评论
Babak
Babak 2025-8-20
Isn't there a function that could do this? Basically keep a row as a row and convert a column vector into a row. Ensuring if x was a row it wouldn't take the `transpose`
Stephen23
Stephen23 2025-8-20
编辑：Stephen23 2025-8-31
Ran in:
@Babak here are two approaches that work regardless of the input size:
x = [5;10;9;25]
x = 4×1
5 10 9 25
<mw-icon class=""></mw-icon>
<mw-icon class=""></mw-icon>
y = reshape(x,1,[]) % more efficient
y = 1×4
5 10 9 25
<mw-icon class=""></mw-icon>
<mw-icon class=""></mw-icon>
y = x(:).' % less writing
y = 1×4
5 10 9 25
<mw-icon class=""></mw-icon>
<mw-icon class=""></mw-icon>

请先登录，再进行评论。

Babak
Babak 2025-8-20
编辑：DGM 2025-8-31
Ran in:
x = [5;10;9;25]; % a column vector
reshape(x, 1, length(x)) % a row vector
ans = 1×4
5 10 9 25
<mw-icon class=""></mw-icon>
<mw-icon class=""></mw-icon>
y = [5 10 9 25]; % a row vector
reshape(y, 1, length(y)) % still a row vector
ans = 1×4
5 10 9 25
<mw-icon class=""></mw-icon>
<mw-icon class=""></mw-icon>
% create an anonymous function to do the job
f = @(x)reshape(x,1, length(x));
% when applied to the previous vectors, the results are as before
f(x)
ans = 1×4
5 10 9 25
<mw-icon class=""></mw-icon>
<mw-icon class=""></mw-icon>
f(y) % and another
ans = 1×4
5 10 9 25
<mw-icon class=""></mw-icon>
<mw-icon class=""></mw-icon>
  1 个评论
DGM
DGM 2025-8-31
Ran in:
Edited to run the code for demonstration purposes; added comments.
Note that there are few cases where length() can be used incautiously without inviting problems. Unless you're making sure that the input is strictly a vector, you're waiting on a confusing error about the wrong number of elements.
If you want to explicitly specify the output size, use numel() instead of length(). The usefulness of the output may be zilch for a reshaped matrix, but at least it avoids the confusing error and returns a vector. Specifying a slack dimension as in @Stephen23's example does the same, and is more succinct.
x = [1 2 3 4].'; % a column vector or row vector
y = reshape(x,1,[]) % to a row vector
y = 1×4
1 2 3 4
<mw-icon class=""></mw-icon>
<mw-icon class=""></mw-icon>
x = [1 3 5; 2 4 6]; % oops we didn't constrain the input dimensionality!
y = reshape(x,1,numel(x)) % but at least we got a vector without error
y = 1×6
1 2 3 4 5 6
<mw-icon class=""></mw-icon>
<mw-icon class=""></mw-icon>
y = reshape(x,1,[]) % same thing, more succinct, easier to read/remember
y = 1×6
1 2 3 4 5 6
<mw-icon class=""></mw-icon>
<mw-icon class=""></mw-icon>
y = reshape(x,1,length(x)) % you're trying to fit 6 elements in a 1x3 vector
Error using reshape
Number of elements must not change. Use [] as one of the size inputs to automatically calculate the appropriate size for that dimension.

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Creating and Concatenating Matrices 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by