MATLAB Answers


How can I select items in a double list?

Asked by Jonathan Bijman on 14 Jun 2019
Latest activity Commented on by 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:
Only appears the first element and not the 2nd and 3rd ones.
How can I show the three elements?
Thank U


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2 Answers

Answer by Walter Roberson
on 14 Jun 2019
 Accepted Answer

Now the groups of 3 appear as columns.


I wrote:
BC = num2cell(reshape(T_C,3,[]), 1);
[T_A8, T_C5, T_E1] = deal(BC{:});
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{:});
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);
Thank U again @Walter Roberson for your wisdom and help.
Very thankful =)

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Answer by Image Analyst
on 14 Jun 2019

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


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...)
Thanks for youimage.pngr help
Sounds like, from your comment to Walter, that you've got it all solved now, so there is no need for me to answer anymore.
Yes, but I appreciate your help @Image Analyst anyway.
Thank U =)

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