column circular permutaion on a matrix

2 次查看（过去 30 天）
Abhishek Bakhla
Abhishek Bakhla 2020-4-20
评论： Abhishek Bakhla 2020-4-23
How can I move all the elements of a particular column circulary upwards or circularly downwards by some shift s. I have a matrix A = [ 1 2 3 4; 5 6 7 8; 9 10 11 12; 13 14 15 16] and shift columns 1, 2, 3 and 4 by shifts 2, 1 , 3 and 2 respectively then I get the matrix A as A = [9 6 15 12; 13 10 3 16; 1 14 7 4; 5 2 11 8].

请先登录，再回答此问题。

采纳的回答

Ameer Hamza
Ameer Hamza 2020-4-20
Try this
A = [ 1 2 3 4; 5 6 7 8; 9 10 11 12; 13 14 15 16];
B = [9 6 15 12; 13 10 3 16; 1 14 7 4; 5 2 11 8];
shift = [2, 1, 3, 2];
C = A; % make a copy
for i=1:numel(shift)
C(:,i) = circshift(C(:,i), -shift(i));
end
Result
>> isequal(B, C)
ans =
logical
1

更多回答（2 个）

Ilian
Ilian 2020-4-20
If you just want to rotate the rows this could work:
s = -3; % shift (both positive and negative values work)
rows = size(A,1);
B = [A(mod(s-rows,rows)+1:end,:); A(1:mod(s-rows,rows),:)];
Stephen23
Stephen23 2020-4-21
No loops:
>> A = [1,2,3,4;5,6,7,8;9,10,11,12;13,14,15,16];
>> S = [2,1,3,2]; % shifts
>> [R,C] = ndgrid(1:4,1:4);
>> B = A(sub2ind([4,4],1+mod(S+R-1,4),C))
B =
9 6 15 12
13 10 3 16
1 14 7 4
5 2 11 8

类别

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

标签

产品

Community Treasure Hunt

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

Start Hunting!

Translated by