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

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?

Answer 1

[dpb]

" Would taking these 3 columns apart help...?"

No.

tT.Diff=[false;any(diff(tT.X),2)];

[Richard Michaud Langis]

Here is what I am using to import my .csv file,

T = readtable('spreadsheet1.csv');

and here is a sample of a few rows, reminder that I only want to count if there last 3 column of a row is different than the last one.

182 39 61 1 0 0 0 1

41 125 51 0 0 0 1 0

119 149 145 0 0 0 0 1

51 37 104 1 0 0 0 1

[dpb]

So, what's the problem -- other than you apparently have already got the separate variables?

Put them back together again and the above works.

The above is definitely ambiguous to try to interpret, what does

head(T)

return?

[Richard Michaud Langis]

head(T)

ans =

  8×8 table

    Var1    Var2    Var3    Var4    Var5    Var6    Var7    Var8
    ____    ____    ____    ____    ____    ____    ____    ____

     0       0       0       0       0       0       0       1  
     0       0       0       0       0       0       0       1  
     0       0       0       0       0       0       0       1  
     0       0       0       0       0       0       0       1  
     0       0       0       0       0       0       0       1  
     0       0       0       0       0       0       0       1  
     0       0       0       0       0       0       0       1  
     0       0       0       0       0       0       0       1  

So Basically, I want to count how many times the data in Var6, Var7, Var8 are different in one row from the previous one.

[dpb]

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.