How can I change value of array?

Hi!

I've an array that is A but I'd like to create another array, B, that containes in order the position of this values.

For example: if A is [1000,700,500,350,200,100,50,15], B must be [8,7,6,5,4,3,2,1].

I tried to do:

a = 8; % a is number of values in array
A = [1000,700,500,350,200,100,50,15];
for i = 1:a
B = A(i)
end

but B is not an array. How can I do?

[Dennis]

So B is just descending from length of A?

 B=fliplr([1:length(A)])

You need to change B to B(i) in your code to get a vector. Right now you are overwriting B in every iteration. But then B would have the same values as A.

[Stephen23]

" I'd like to create another array, B, that containes in order the position of this values"

Then use sort:

[~,B] = sort(A)

EDIT: see also earlier question, with an impossibly complex approach to this problem:

https://www.mathworks.com/matlabcentral/answers/398185-how-can-i-identify-value-of-an-array

[sc]

'So B is just descending from length of A?'

No, because for example: if: A = [1000,500,700,350,100,200,50,15]; B must be B = [8,6,7,5,3,4,2,1].

In practice I should associate the values of A to the values of B, but values however may not be descendants.

It's hard to explain: I would like to create the ascending order of A's values, but insert them in order of appearance in B.

Is it possible?

[Jan]

@sc: Please stop closing your question, when they got accepted answers already. After closing the questions are deleted, and this would remove the invested time of the ones, who help you. This is counter-productive in a public forum.

Answer 1

[Jan]

Maybe:

B = numel(A):-1:1

if the array A is sorted already. Otehrwise:

[~, B] = sort(A, 'ascend')