how to interchange the elements of a vector/matrix?

4 次查看（过去 30 天）
Muhammad Ridwanur Rahim
评论： lokender Rawat 2018-5-8
hi
a,b,c,d all are 2x1 matrices.
i will run a for loop and with each loop the elements of matrix x will increase.
example-
for i=1, x=[a1]
for i=2, x=[a1 b1 b2]
for i=3, x=[a1 b1 b2 c1 c2 c3 c4]
for i=3 x=[a1 b1 b2 c1 c2 c3 c4 d1 d2 d3 d4 d5 d6 d7 d8]
now after i=2, i want to rearrange the matrix to look like
y=[b1 a1 b2].
after i=3, i want to rearrange the matrix to look like
y=[c1 b1 c2 a1 c3 b2 c4]
after i=4, i want to rearrange the matrix to look like
y= [d1 c1 d2 b1 d3 c2 d4 a1 d5 c3 d6 b2 d7 c4 d8].
please tell me how i can do this?
basically all the new elements will be placed in between the existing elements.
  3 个评论
显示 1更早的评论
Muhammad Ridwanur Rahim
Muhammad Ridwanur Rahim 2018-5-7
hi,
i will run a function and the function will output
for i=1 a 2x1 matrix
for i=2, a 2x2 matrix
for i=3, a 2x3 matrix
for i=4, a 2x4 matrix.
and then i would like to rearrange the columns of the matrices as mentioned in the original post.
a,b,c,d are all basically the outputs of the function.
for better understanding, i have denoted them different name so that i could explain how i want them to be rearranged.
Muhammad Ridwanur Rahim
Muhammad Ridwanur Rahim 2018-5-7
basically i run run a function in a loop.
for i=1, function_output=[a11; a21], rearrange_output=[a11; a21]
for i=2, function_output=[b11 b12;b21 b22], rearrange_output=[b11 a11 b12; b21 a21 b22]
for i=3, function_output=[c11 c12 c13 c14;c21 c22 c23 c24], rearrange_output=[c11 b11 c12 a11 c13 b12 c14; c21 b21 c22 a21 c23 b22 c24]
and so on and so forth.

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

Stephen23
Stephen23 2018-5-7
This works:
for k = 1:4
% fake data:
new = zeros(2,pow2(k-1));
new(:) = 10*k+(1:numel(new));
% zip data together:
if k==1
out = new
else
out = [reshape([new(:,1:end-1);out],2,[]),new(:,end)]
end
end
It displays this in the command window:
out =
11
12
out =
21 11 23
22 12 24
out =
31 21 33 11 35 23 37
32 22 34 12 36 24 38
out =
41 31 43 21 45 33 47 11 49 35 51 23 53 37 55
42 32 44 22 46 34 48 12 50 36 52 24 54 38 56

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