Filtering a Single Column of One Table Based on Multiple Criteria from Another Table.

To start I am working on a different network and unable to show my code and will do my best to explain.

I have 2 tables (Table A starts at 130x19, Table B starts at 5000x8) that share a single variable header that contains ID numbers. I have successfully filtered down table A to 10x19. What I am having trouble doing currently is taking those 10 ID numbers to filter table B to show all rows (with all information) that have any of the unique 10 IDs.

Answer 1

[Star Strider]

I’m not sure that I fully understand your problem, however the join function (or one of its friends innerjoin or outerjoin) may be the solution.

[Chad]

I am not trying to join the two tables, though I did explore this option. Each table that I am working with has a specific need of information. For instance, in Table A I got the information I needed based on a simple filter to only show a country using the following:

idx = (strcmp(TableA(VariableA.Country == 'United States' == 1);

TableAFilter = Table(idx,:);

So now I have to take the 10 different ID numbers from TableAFilter, Variable B and use those on Table B Variable B so that out of the 5000 rows I can create a new table that only shows the 50 or so instances that each ID shows up. I attempted something similiar but I only recieved the first 10 rows of the second table.

[Star Strider]

I still (apparently) fail to understand the problem.

Another option could be ismember (or ismembertol) for the comparisons.

[Chad]

It's ok and you were correct about the join. It is a inner join that did the trick, and after some time I was able to get some more help with the AI Chat Playground and verified that it does what I needed it to do. Thank you for help.

% Sample data for the first table
data1 = table(["A"; "B"; "C"; "D"; "E"; "A"; "C"], [1; 2; 3; 4; 5; 6; 7], 'VariableNames', {'Category', 'Value'});

% Sample data for the second table (filter criteria)
data2 = table(["A"; "C"], 'VariableNames', {'Category'});

% Filter the first table based on values in the second table
filteredData = innerjoin(data1, data2, 'Keys', 'Category');

% Display the filtered table
disp(filteredData);

[Siddharth Bhutiya]

If you only want the data from the data1 table then as Star Strider suggested above, using ismember + subscripting will also do the trick.

data1 = table(["A"; "B"; "C"; "D"; "E"; "A"; "C"], [1; 2; 3; 4; 5; 6; 7], 'VariableNames', {'Category', 'Value'});
data2 = table(["A"; "C"], 'VariableNames', {'Category'});
filteredData = data1(ismember(data1.Category, data2.Category),:)

filteredData = 4x2 table
    Category    Value
    ________    _____

      "A"         1  
      "C"         3  
      "A"         6  
      "C"         7  

Basically what the expression means is give me all the rows from data1 where data1's Category matches one of data2's Categories, which I believe is what you want.

[Star Strider]

@Chad —

My pleasure!

If my Answer helped you solve your problem, please Accept it!

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