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I am trying to create a function form a vector from my matrix and I do not understand where my mistake is?

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Laurence Guevremont
Laurence Guevremont on 27 Sep 2016
Commented: dpb on 29 Sep 2016
function A=combined (V)
for V(k)= A(i,j)
k=1;
for
i=1;
j=1;
k=k+1;
end
end

  3 Comments

James Tursa
James Tursa on 27 Sep 2016
Can you describe in words what the input and output are? And can you provide a small example of an input V and desired output A?
Laurence Guevremont
Laurence Guevremont on 27 Sep 2016
Ok so I need transform my matrix into a vector so example: A= [1 2 3; 4 5 6; 7 8 9] And then form a vector A A=[1 2 3 4 5 6 7 8 9]
My function right now does not work, there is a mistake on line 2
dpb
dpb on 27 Sep 2016
Indeed, there are several issues but the one of defining the for...end loop indices and range is key. To do the requested function, using "linear addressing" would be a good way to proceed. Look those up in the documentation and study for loops...

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Answers (3)

Moe_2015
Moe_2015 on 27 Sep 2016
Edited: Moe_2015 on 27 Sep 2016
You should avoid using a for loop here. You can do something like this:
function myVector=combined(myMatrix)
myVector = reshape(myMatrix,1,numel(myMatrix));
end

dpb
dpb on 27 Sep 2016
"...transform my matrix into a vector"
Really don't need a function for this; Matlab has syntax to do it already. A previous answer shows reshape, except I'd suggest to simply use it ( reshape, that is) inline as shown there in the function instead.
There's another Matlab idiom that's even more compact--
A=A(:).'; % convert A of unspecified dimensions to row vector
NB: the .' transpose operator to return the requested row vector instead of the column vector colon returns.

James Tursa
James Tursa on 28 Sep 2016
Here is an outline of what you need to be using for the for loops (seems to be a requirement for this assignment).
% Insert any initialization code here
for i = 1:size(V,1)
for j = 1:size(V,2)
% Insert your assignment etc code here
end
end

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