how can we compare two arrays eg 'data' and 'aa' ,when 'data' matches any value of 'aa' i want it to return past values of data that are before that common value of data and aa....in an array

clc
close all
clear all
[data, fs]=audioread('E:\MATLAB\R2017a\examples\audio\focus_good.wav');
sound(2*data,45000)
aa = [0, 0.0001, 0.0002, 0.0003, 0.0004];
u=data(:);  % reshape
for i=1:length(u)
    for j=1:length(aa)
 if data(i)==aa(j)
     s=i                   % saving the point or number of digit where value matched
     *q=data(0:i)*           % wanted to return past value but not working**
 else
 end
    end
end

i am having the problem in returning past values, you can check the asterick command in code... please help me out.

Answer 1

[Walter Roberson]

ismember(aa, dd), take the second output, index it at the first output, take the min() of the result. That will be the index of the first entry in dd that was in common so return everything in dd before that index.

[Walter Roberson]

[tf, idx] = ismember(aa,dd);
result = dd(1:min(idx(tf))-1);

Answer 2

[Birdman]

tempRes=setdiff(aa,data) %temporary solution, will be changed
[~,idx]=ismember(aa,data)
[~,idx]=max(idx)
tempRes(aa(idx):end)=[]