I want to add a column that counts the passes for this test. When the values in the first column are between 0-300 seconds, I want to consider that pass 1, etc.

I want to add a column that counts the passes for this test. When the values in the first column are between 0-300 seconds, I want to consider that pass 1, etc.

I figured out how to add a new column:

%Add new columnm to mark passes
passestest= zeros(size(CETR,1),1);  
CETR=[CETR,passestest];

I would then like to find the averages for each of the passes (averages of all rows in pass 1).

[Walter Roberson]

Another way to add a new column:

CETR(end,end+1) = 0;

[Marian Kennedy]

Thanks! That is much cleaner!

Answer 1

[Walter Roberson]

Possibly you want to use histcounts(), passing in edges like [0 300 450 ....] to count 0 <= x < 300, 300 <= x < 450, and so on

[Marian Kennedy]

Is there a way to automate this process?

for i=1:numel(CETR1(:,1)) %numel means number of elements in CETR1(:,1)
    if CETR1(i,1)<300
        CETR1(i,12)=1;

      elseif CETR1(i,1)<600
          CETR1(i,12)=2;

      elseif CETR1(i,1)<900
          CETR1(i,12)=3;
      end
  end

[Steven Lord]

The histcounts function returns bin counts as its first output and bin membership numbers in its third output. The discretize function returns bin membership numbers in its first output. In this case I'm going to get histcounts tell me what edges it used and reuse those edges in discretize. If you know the bin edges you want to use, you can specify them in either histcounts or discretize.

x = randperm(100, 25);
[bincounts1, edges1, binlocations1] = histcounts(x)
binlocations2 = discretize(x, edges1)
isequal(binlocations1, binlocations2) % true

From your description you're more interested in binlocations1 (or binlocations2, since they're the same) than bincounts1.

Answer 2

[Guillaume]

You can do the discretisation (as that's what you want is called) and the addition as a new column all in one go:

CETR1(:, end+1) = discretize(CETR1(:, 1), [0 300 600 900])

No loop needed of course.