how automatically label multiple outputs in the loop?

4 vues (au cours des 30 derniers jours)
frwmetric
frwmetric le 20 Mai 2013
hi how automatically label multiple outputs in the loop? I do not know it is possible or not... may be it is very basic...
I mean basically
for i=1:3
x=i^2
end
here the outputs
x =
1
x =
4
x =
9
I want to label those x st
x(1)=1
x(2)=4
x(3)=9

Réponses (2)

Dr. Seis
Dr. Seis le 20 Mai 2013
If you know how many elements in x there will be (3 in your example), then it is best to initialize the output:
x = zeros(3,1); % 3 rows and 1 column of zeros
Then perform your calculations:
for i = 1 : 3
x(i) = i^2;
end
  4 commentaires
Image Analyst
Image Analyst le 20 Mai 2013
You can initialize to the max you ever expect to see, and then truncate later once you know the number of elements you actually need:
% Preallocate space for as many as 3 million elements.
x = zeros(3000000,1); % 3 million rows and 1 column of zeros
Then perform your calculations:
for i = 1 : 2000000 % 2 million.
x(i) = i^2;
end
% Truncate to known length of 2 million elements.
x = x(1:2000000);
Iain
Iain le 20 Mai 2013
You could also do the loop in the opposite direction. High indices to low indices.

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José-Luis
José-Luis le 20 Mai 2013
Modifié(e) : José-Luis le 20 Mai 2013
x = 1:3; %Creating a vector of values
your_result = x.^2; %squaring element by element
x(1)
x(2)
x(3)
I would recommend you read the Getting started part of the documentation.

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