ismember(A,B,'rows') indexing

Hello everyone,

I would like to compare two cells, want to see if element of A is a member of B, If yes then it should return 1 otherwise 0.

Size of A is 189x1 and Size of B is 108x1.

I used:

C = ismember(A,B,'rows');

It returned logical o,1. With Size of 189x1, Perfect.

But now. I want Values of B (108x1) sorted same like C with Size 189x1.

Any help would be appreciated.

Thank you.

Regard,s

Waqar Ali

[Geoff Hayes]

Waqar - please clarify what you mean by I want Values of B (108x1) sorted same like C with Size 189x1. Do you want B to be transformed from a 108x1 array into a 189x1 array?

[Waqar Ali Memon]

Hello Geoff Hayes,

Thank you so much for your reply.

Yes I want to transform B from a 108x1 array into a 189x1 array :-).

Thanks again :-)

[dpb]

Well, that's easy enough -- add 81 elements on the end. The question is, what are the new elements to contain? I don't see there's any correlation between the two requests.

[Waqar Ali Memon]

Hello dpb,

Adding 81 elements will make it wrong. Since i require Output like following:

For suppose, Cell1 contains following elements.

Cell1: Had 2 columns, I have concentrated them and shows as follows.

1. 'ADSµSOIC8'
2. 'AVX0603'
3. 'ELN'
4. 'ELNH10'
5. 'EPC'
6. 'EPC0603'
7. 'FAGDO214AA'
8. 'FAGDO214AA (SMB)'
9. 'FAGDO214AB'
10. 'FAGDO214AC'
11. 'FAGSMA'
12. 'FAGSOD123W'
13. 'FAGSOD128'
14. 'FSLLQFP-64 ePAD'
15. 'FSLLQFP80-ePad'

Cell2: Had 3 columns, I have concentrated first 2 columns and shows as follows but Cell2 only contains 10 random elements ( In this example only).

1. 'ADSµSOIC8' '1'
2. 'AVX0603' '3'
3. 'ELN' '2'
4. 'EPC' '2'
5. 'EPC0603' '3'
6. 'FAGDO214AA' '10'
7. 'FAGDO214AC' '1'
8. 'FAGSOD123W' '5'
9. 'FAGSOD128' '2'
10. 'FSLLQFP-64 ePAD' '1'

I want to create new cell3: That should contain all elements of Cell1: (I have already created).

Now I would like to add 2nd Column in Cell1 which should show values of Cell2 which should be in same order of Cell1 i.e. 15x1.

i.e. output should be like:

Required Output:

1. 'ADSµSOIC8' '1'
2. 'AVX0603' '3'
3. 'ELN' '2'
4. 'ELNH10' '0'
5. 'EPC' '2'
6. 'EPC0603' '3'
7. 'FAGDO214AA' '10'
8. 'FAGDO214AA (SMB)' '0'
9. 'FAGDO214AB' '0'
10. 'FAGDO214AC' '1'
11. 'FAGSMA' '0'
12. 'FAGSOD123W' '5'
13. 'FAGSOD128' '2'
14. 'FSLLQFP-64 ePAD' '1'
15. 'FSLLQFP80-ePad' '0'

This is the best explanation i guess :-)

Thank you everyone.

Answer 1

[Stephen23]

>> one = {'ADSµSOIC8';'AVX0603';'ELN';'ELNH10';'EPC';'EPC0603';'FAGDO214AA';'FAGDO214AA (SMB)';'FAGDO214AB';'FAGDO214AC';'FAGSMA';'FAGSOD123W';'FAGSOD128';'FSLLQFP-64 ePAD';'FSLLQFP80-ePad'}
one = 
    'ADSµSOIC8'
    'AVX0603'
    'ELN'
    'ELNH10'
    'EPC'
    'EPC0603'
    'FAGDO214AA'
    'FAGDO214AA (SMB)'
    'FAGDO214AB'
    'FAGDO214AC'
    'FAGSMA'
    'FAGSOD123W'
    'FAGSOD128'
    'FSLLQFP-64 ePAD'
    'FSLLQFP80-ePad'
>> two = {'ADSµSOIC8','1';'AVX0603','3';'ELN','2';'EPC','2';'EPC0603','3';'FAGDO214AA','10';'FAGDO214AC','1';'FAGSOD123W','5';'FAGSOD128','2';'FSLLQFP-64 ePAD','1'}
two = 
    'ADSµSOIC8'          '1' 
    'AVX0603'            '3' 
    'ELN'                '2' 
    'EPC'                '2' 
    'EPC0603'            '3' 
    'FAGDO214AA'         '10'
    'FAGDO214AC'         '1' 
    'FAGSOD123W'         '5' 
    'FAGSOD128'          '2' 
    'FSLLQFP-64 ePAD'    '1' 
>> [X,Y] = ismember(one,two);
>> out = one;
>> out(:,2) = {'0'};
>> out(X,2) = two(Y(X),2)
out = 
    'ADSµSOIC8'           '1' 
    'AVX0603'             '3' 
    'ELN'                 '2' 
    'ELNH10'              '0' 
    'EPC'                 '2' 
    'EPC0603'             '3' 
    'FAGDO214AA'          '10'
    'FAGDO214AA (SMB)'    '0' 
    'FAGDO214AB'          '0' 
    'FAGDO214AC'          '1' 
    'FAGSMA'              '0' 
    'FAGSOD123W'          '5' 
    'FAGSOD128'           '2' 
    'FSLLQFP-64 ePAD'     '1' 
    'FSLLQFP80-ePad'      '0' 

[Waqar Ali Memon]

Hello Stephen Cobeldick,

Thank you for your time.

On executing your code, I am getting error: Index exceeds matrix dimensions. :-(

[Stephen23]

@Waqar Ali Memon: showing part of an error message is not very helpful. Please show the complete error message. This means all of the red text.

It would also help if you showed/uploaded the code that you are using.

[Waqar Ali Memon]

Now it is working, i restarted the program.

Thank you so much :-)

[Guillaume]

One must wonder why an answer is accepted to then say it doesn't work.

As I've pointed out in my answer, you haven't given us enough details to know what you're doing exactly, so it's likely that no answer will work straight out of the box, but you should be able to work it out from there.

As said, you need to use the 2nd return value of ismember.

I'd recommend you not use X and Y as variable names but soemthing more meaningful

Answer 2

[joe]

function result = compareMatrices( A,B)
    result = zeros(size(A,1),size(B,2)); % generate matrix with the same size as the A
    for i=1:numel(A) % this loop checkes the existens of all elements of A in B 
        [~,index]=ismember(A{i,1},B); 
        if index~=0   % if any element of A exists in B
            result{i,1} = 1;   % set 1 in the same position where the existens detected
        end
    end
end

[Waqar Ali Memon]

Hello joe,

Thank you for your help. By executing your code i am getting following error:

function result = compareMatrices(AA,BB)

↑

Error: Function definitions are not permitted in this context.

Any suggestion ?

[Guillaume]

Functions need to go into their own files or at the end of a script file. You can't paste function definitions on the command line.

joe had the correct concept of using the 2nd return value of ismember. However, a loop is certainly not needed and just unnecessary complexity.

[Waqar Ali Memon]

I have added them in end of a script file, it ran but did not give output.

[joe]

if you have matrices with elements of deferent types

try to call the function like this: compareMatrices(string(A), string(B))

[Waqar Ali Memon]

Thanks joe for yOur time :-)

Answer 3

[Guillaume]

If the two cell arrays don't have the same number of columns, you're obviously not using ismember(A, B, 'rows') but something slightly more complex. I'm taking a guess here.

You also haven't said what needs to go in the result, when the row of A is not found in B.

In any case, you just have to use the 2nd output of ismember

[isfound, where] = ismember(A(:, 1), B(:, 1));  %compare column 1 of A and column 1 of B
C = [A(isfound), B(where(isfound), 3)];  %get rows of A found in B together with the matching value of column 3 of B

Adapt as necessary.

[Waqar Ali Memon]

This returned again the actual size. Thanks Man, Problem solved :-)