how to find index from matrix in another matrix?

4 ビュー (過去 30 日間)
Lilya
Lilya 2022 年 7 月 26 日
コメント済み: Fangjun Jiang 2022 年 7 月 27 日
Hi all,
I have two different 3d matrices (A=72*46*2192) and (B=72*46*2192), in which I want to find the indices equal to 4 and 5 from A in B.
The result should be a 3d matrix as well, not linear indices.
Any help would be appreciated.
  2 件のコメント
Lilya
Lilya 2022 年 7 月 27 日
Thanks for your responce David.
A = rand(2,3,4);
B=rand(2,3,4);
Matrix A should have elements = 4 and 5.
I want to use the index of those 4 and 5 in A to find the corresponding elements in B.

サインインしてコメントする。

回答 (1 件)

Fangjun Jiang
Fangjun Jiang 2022 年 7 月 26 日
編集済み: Fangjun Jiang 2022 年 7 月 27 日
%C is the logical index matrix.
A=zeros(2,3,4);
A(:,:,4)=4;
A(:,3,4)=5;
C=or(A==4,A==5)
C = 2×3×4 logical array
C(:,:,1) = 0 0 0 0 0 0 C(:,:,2) = 0 0 0 0 0 0 C(:,:,3) = 0 0 0 0 0 0 C(:,:,4) = 1 1 1 1 1 1
%To use it to select corresponding elements in B
B=rand(2,3,4);
B_select=B(C)
B_select = 6×1
0.2953 0.0888 0.5716 0.4577 0.5288 0.3675
LinearIndex=find(C);
[SubX,SubY,SubZ]=ind2sub(size(C),LinearIndex)
SubX = 6×1
1 2 1 2 1 2
SubY = 6×1
1 1 2 2 3 3
SubZ = 6×1
4 4 4 4 4 4
  2 件のコメント
Fangjun Jiang
Fangjun Jiang 2022 年 7 月 27 日
See the updated answer to understand
  1. Logical index
  2. Linear index
  3. Subscript index

サインインしてコメントする。

Community Treasure Hunt

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

Start Hunting!

Translated by