# How to count the amount of times certain row changes in a table?

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Richard Michaud Langis on 3 May 2022
Edited: dpb on 3 May 2022
So I have a table, 8 columns and a varying amount of rows. The last 3 columns are always going to be [ 1 0 0 ], [ 0 1 0 ] or [ 0 0 1 ]. I would like to be able to count the amount of times, one row of these 3 columns that are not the same as the previous one (ex: row1 [ 0 1 0 ], row2 [ 0 1 0 ], row 3 [ 0 0 1], this counts as 2). Would taking these 3 columns apart help, if so how?

dpb on 3 May 2022
" Would taking these 3 columns apart help...?"
No.
tT.Diff=[false;any(diff(tT.X),2)];
dpb on 3 May 2022
Edited: dpb on 3 May 2022
Yes, so what's the problem? It's a little simpler in your first scenario where the columns were all in one array, but the same idea.
tDiff=[false; any(diff(tT{:,{'Var6','Var7','Var8'}}),2)];
See the link @doc:table -- specifically the subsection at bottom on accessing data from a table.
The count is simply
sum(tDiff)
If you don't need to know where the changes are, then you don't need the new table variable, it can just be a temporary without assignment.

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