CODEWITHSUNDEEP
matlabdatetimematrix
litmus
litmus

Reputation: 107

How to match and copy time-data from one matrix to another?

In MATLAB (R2015a), I have two large matrices that can be simplified as:

A = [ 24 10 830; 24 15 830; 150 17 945; 231 40 1130; 231 45 1130]

(note that in A, column 3 is the time for the event cataloged in column 1) and

B = [24 13; 150 29; 231 43]

How can I match and copy the time-data from column 3 in matrix A, to a matching and filtered event column in matrix B?

For example, I want the value 24 from first column in B to be matched with value 24 from first column in A, and then copy the corresponding time-data in A's third column (for 24 it's 830, for 150 it's 945 etc.) into B. This should result into our new B with the time-data from A:

B = [24 13 830; 150 29 945; 231 43 1130]

I relatively new to MATLAB so any help is much appreciated!

Upvotes: 1

Views: 24

Answers (1)

NKN
NKN

Reputation: 6434

First find the location of the elements in the first row of B in the first row of A using the ismember function. And then use those locations to construct the new matrix.

[~,Locb] = ismember(B(:,1),A(:,1));
Bnew = [B A(Locb,3)]


Bnew =

          24          13         830
         150          29         945
         231          43        1130

This is a fast way that comes to my mind. There might be some singularities that needed to be checked more thoroughly.

Upvotes: 2

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