Find subscripts in a 3D matrix

조회 수: 10 (최근 30일)
Fernando Montero
Fernando Montero 2021년 1월 28일
댓글: Fernando Montero 2021년 1월 28일
I have a 3D matrix, called A, and I want to find the subscripts for all places where elements of vector B appear. The elements of B apper more than one time in the matrix A.
I tried it using function subs to obtain directly the susbsripts, but I obtained a result where many page numbers are wrong (it shows a higher number (5) than the existing pages (3)). Bellow the code:
A(:,:,1)=[1 2 ; 3 3 ; 5 7 ; 4 2];
A(:,:,2)=[9 1 ; 4 4 ; 9 2 ; 4 6];
A(:,:,3)=[2 4 ; 7 4 ; 3 1 ; 6 4];
B = [9 4 1];
[row,col,page] = ind2sub(size(A),find(A(:)==B))
Also I tried using function find to obtain the linear indexes to later convert them to subscripts; however, I only obtain the first place were the element is placed on the matrix:
n = arrayfun(@(x) find(A==x,1),B);
[row, col, page] = ind2sub(size(A), n);

채택된 답변

Walter Roberson
Walter Roberson 2021년 1월 28일
A(:,:,1)=[1 2 ; 3 3 ; 5 7 ; 4 2];
A(:,:,2)=[9 1 ; 4 4 ; 9 2 ; 4 6];
A(:,:,3)=[2 4 ; 7 4 ; 3 1 ; 6 4];
B = [9 4 1];
[row,col,page] = ind2sub(size(A),find(ismember(A,B)))
row = 12×1
1 4 1 2 3 4 1 2 1 2
col = 12×1
1 1 1 1 1 1 2 2 2 2
page = 12×1
1 1 2 2 2 2 2 2 3 3
  댓글 수: 4
Walter Roberson
Walter Roberson 2021년 1월 28일
find(ismember(A,B)) would be linear
sub2ind(size(A), row,col,page)
if you need to reconstruct linear
Fernando Montero
Fernando Montero 2021년 1월 28일
Thanks again!

댓글을 달려면 로그인하십시오.

추가 답변 (0개)

카테고리

Help CenterFile Exchange에서 Spline Postprocessing에 대해 자세히 알아보기

Community Treasure Hunt

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

Start Hunting!

Translated by