# How can I select items in a double list?

7 views (last 30 days)
Jonathan Bijman on 14 Jun 2019
Commented: Jonathan Bijman on 14 Jun 2019
Hi everyone!
I have a variable which is (105 x 1 double) and I need to select from the first item to 3rd, from 4th item to 6th and from 7th item to 9th.
When, for instance, I apply:
TA8=T_C((1:3):1)
Only appears the first element and not the 2nd and 3rd ones.
How can I show the three elements?
Thank U

Walter Roberson on 14 Jun 2019
reshape(T_C,3,[])
Now the groups of 3 appear as columns.

Jonathan Bijman on 14 Jun 2019
I wrote:
BC = num2cell(reshape(T_C,3,[]), 1);
[T_A8, T_C5, T_E1] = deal(BC{:});
Appears:
Error using deal (line 37)
The number of outputs should match the number of inputs.
Error in T_Ambos (line 26)
[T_A8, T_C5, T_E1] = deal(BC{:});
Walter Roberson on 14 Jun 2019
You need one output for each column.
Though I thought you were giving examples and wanted to continue for all of the groups. If you just want those specific parts then just do three assignments,
T_A8 = T_C(1:3);
T_C5 = T_C(4:6);
T_E1 = T_C(7:9);
Though seeing your response to someone else, it looks like what you want is
T_A8 = T_C(1:3:end);
T_C5 = T_C(2:3:end);
T_E1 = T_C(3:3:end);
Jonathan Bijman on 14 Jun 2019
Thank U again @Walter Roberson for your wisdom and help.
Very thankful =)

Image Analyst on 14 Jun 2019
Try
TA8 = T_C(1:3);
etc. Or for all of them in turn:
for k = 1 : 3 : length(T_C) % Starting at 1, 4, 7, etc....
TA8 = T_C(k:k+2); % Get this group of 3 elements.
% Now do something with TA8
end

Jonathan Bijman on 14 Jun 2019
I'm sorry, my english sometimes is bad =(.
I hope you get it with this image.
I want to associate all A8 (corresponds to 1, 4, 7, etc...), C5 (corresponds to 2, 5, 8, etc...) and E1 (3, 6, 9, etc...)