MATLAB: Remove rows in an array containing a non-matching element

arraynon-matching elementsremoverow

I have a datafile data.txt:
gene12 489 483 838
gene82 488 763 920
gene31 974 837 198
gene45 489 101 378
gene59 89 827 138
I have another data file genelist.txt that lists just genes I'm interested in for my study:
gene45
gene59
gene61
I want to modify the first dataset by removing all rows where the gene isn't found in the second list so basically end up with this array:
gene45 489 101 378
gene59 89 827 138
How do I go about doing this?

Best Answer

Probably the easiest:
geneswithdata = readtable('data.txt');  %load file as a table
geneswithdata.Properties.VariableNames{1} = 'genes';  %rename first column for clarity (optional). 
%I would also rename all the other columns
genesonly = readtable('genelist.txt');  %load as a table
genesonly.Properties.VariableNames = {'genes'};  %rename columns. Common columns must have the same name
filteredgenes = innerjoin(genesonly, geneswithdata);
Done.
Using ismember that last line could be done as:
found = ismember(geneswithdata, genesonly);
filteredgenes = geneswithdata(found, :);
Using intersect (rather than setdiff) it could be done as:
[~, tokeep] = intersect(geneswithdata, genesonly);
filteredgenes = geneswithdata(tokeep, :);
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