If B is a matrix,what is the difference between B(1:end) and B(:)

2 次查看（过去 30 天）
Alejandro Duque Salazar
编辑： Stephen23 2020-1-6
If B=[1 2 ; 3 4]
B(1:end) returns [1 3 2 4] as a row vector and B(:) returns it as a column vector.
What is the difference?

请先登录，再回答此问题。

采纳的回答

Stephen23
Stephen23 2020-1-6
编辑：Stephen23 2020-1-6
Given a matrix B:
  • B(1:end) uses linear indexing. The size of the output is the same as the size of the index (which in your example is a 1xN vector).
  • B(:) is a special syntax that always returns a column vector.
Loren Shure's blog explained the first syntax as "C = A(B) produces output the size of B unless both A and B are vectors... When both A and B are vectors, the number of elements in C is the number of elements in B and with orientation of A."
source: https://blogs.mathworks.com/loren/2006/08/09/essence-of-indexing/
See also:
https://www.mathworks.com/company/newsletters/articles/matrix-indexing-in-matlab.html
https://www.mathworks.com/help/matlab/math/array-indexing.html

更多回答（0 个）

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