maximum values in vector
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hi everyone, i have a vector consist of 5000 elements and i need to find the maximum values for 2000 elements with their real index , plz can anyone help me in that? thx
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Star Strider
on 30 Mar 2015
Edited: Star Strider
on 30 Mar 2015
The max function will return only the first maximum in the array if there are more than one. To find all of them, use find:
Example:
Vector = randi(5, 1, 15)
MaxValuesIdx = find(Vector == max(Vector))
produces (in this instance):
Vector =
3 1 2 5 1 3 5 3 4 5 5 2 4 2 1
MaxValuesIdx =
4 7 10 11
EDIT — To get the highest 2000 values, use the sort function.
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Image Analyst
on 30 Mar 2015
Which 2000? The first 2000? Try this
[maxValue, indexOfMaxValue] = max(yourVector(1:2000));
What does "without changing positions mean"? Do you want an array of the same length but all zeros except for the max being in its original location? If so
output = zeros(size(yourVector)); % Initialize
yourVector(indexOfMaxValue) = maxValue; % Assign that one element
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