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POMATLAB how to use FIND function with IF statement
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  1. POMATLAB how to use FIND function with IF statement
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    copied!<p>This question is related to <a href="https://stackoverflow.com/questions/3071558/matlab-how-to-merge-data">How can I merge this data in MATLAB?</a></p> <p>how to use the <code>FIND</code> function with <code>IF</code> statement? e.g. if I have this data:</p> <pre><code>20 10 1 20 11 1 20 15 1 23 10 1 23 10 1 23 12 0 </code></pre> <p>Rule 1: Data of column 3 must be 1.</p> <p>Rule 2: If <code>n</code> is the current index of column 1, if <code>n</code> equal <code>n-1</code> (20=20) of column 1, data of column 2 of index n and n-1 <strong>is merged.</strong> </p> <pre><code>20 21 0 20 15 0 20 0 0 23 20 0 23 0 0 23 12 0 </code></pre> <p><strong>EDITED:</strong> </p> <pre><code>fid=fopen('data.txt'); A=textscan(fid,'%f%f%f'); fclose(fid); in = cell2mat(A)'; %'# fix for SO formatting - Jonas %# rows2mergeFrom are the rows where the second row equals the first row of col 1 %# and where the third column is 1. rows2mergeInto indicates the rows from which the %# values of the following rows should be added rows2mergeFrom = find(in(2:end,1) == in(1:end-1,1) &amp; in(2:end,3) == 1) + 1; out = in; out(rows2mergeFrom-1,2) = out(rows2mergeFrom-1,2) + out(rows2mergeFrom,2); %# data that has been shifted up gets subtracted from the 'rows2mergeFrom'-rows out(rows2mergeFrom,2) = out(rows2mergeFrom,2) - in(rows2mergeFrom,2); %# remove the ones in the third column from any row that has been involved in a %# merge operation out([rows2mergeFrom;rows2mergeFrom-1],3) = 0 fid = fopen('newData.txt','wt'); format short g; fprintf(fid,'%g\t %g\t %g\n',out); %'# Write the data to the file fclose(fid); </code></pre>
 

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