To find a vector subset of a matrix in sequence?

2 vues (au cours des 30 derniers jours)
Vishal Sharma
Vishal Sharma le 27 Jan 2017
Commenté : Vishal Sharma le 27 Jan 2017
I have a vector A = [1 2 3] And another matrix B = [2 3 4 1; 1 2 3 4; 2 4 1 3; 2 3 1 4]
I want to know which row of vector A is subset of Matrix B (in same sequence of A, i.e. 1 2 3
The answer is 2nd row of B matrix

Réponse acceptée

Thibaut Jacqmin
Thibaut Jacqmin le 27 Jan 2017
Here is a solution in one line :
A = [1 2 3];
B = [2 3 4 1; 1 2 3 4; 2 4 1 3; 2 3 1 4];
% Reshape B in a 1D array (all rows in a line)
C = reshape(B', [1, numel(B)]);
% Then use strfind to find a pattern in a string pattern within a string
linear_index = strfind(C, A);
% Compute the row number of the pattern knowing the initial number of columns
row_number = ceil(linear_index/size(B, 2));
% Or do it in a single line :
row_number = ceil(strfind(reshape(B', [1, numel(B)]), A)/size(B, 2));
  2 commentaires
Jan
Jan le 27 Jan 2017
A good idea.
The current version fails, if the searched vector appears over the margins:
B = [2 3 4 1; 2 3 1 4]
But you can filter all occurrences, which do not start between 1 and size(B,2)-length(A).
Vishal Sharma
Vishal Sharma le 27 Jan 2017
please suggest code for this case

Connectez-vous pour commenter.

Plus de réponses (0)

Catégories

En savoir plus sur Characters and Strings dans Help Center et File Exchange

Tags

Community Treasure Hunt

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

Start Hunting!

Translated by