MATLAB: Grouping elements from a table

Question

Hi everyone:

i have a table like this:

Week     Open       High       Low     Close
----     ----       ----       ---     -----
10       1.2        1.4        1.1     1.2
10       1.5        1.7        1.5     1.6
10       1.4        2.1        1.3     2
10       2.2        2.4        2       2.1
11       2          2.1        2       2
11       2.2        2.5        1.1     1.3
12       1.7        1.9        1.6     1.6
12       1.8        1.9        0.6     1.4
12       0.9        1.4        0.8     1

is there a way to get the first element(open), maximum element(high), minimum element(low) and last element (close) for each week? so the result table would be

Week     Open       High       Low     Close
----     ----       ----       ---     -----
10       1.2        2.4        1.1     2.1
11       2          2.5        1.1     1.3
12       1.7        1.9        0.6     1

thanks in advance

Answer 1

Assuming your table is T, the following code can generate what you want.

[group, id] = findgroups(T.Week);
func = @(p, q, r, s) [p(1), max(q), min(r), s(end)];
result = splitapply(func, T.Open, T.High, T.Low, T.Close, group)
Tout = array2table([id, result],...
  'VariableNames', T.Properties.VariableNames);