How to find the two minimum values ?

Hello!

i found a problem. Try to find the minimum position of both values. mycode:

col1 = x(:,1);

col2 = x(:,2);

n = 2;

val = zeros(n,1);

fr = zeros(n,1);

idA = zeros(n,1);

for i=1:n

[val(i) , idA(i)] = min(col2); % Find the minimum and position of col2.

col2(idA(i)) = []; % Remove duplicates in first iteration in col2

end

fr = col1(idA);

final. I got the minimum 2 values but I didn't get the correct position.I got the same position from the last iteration.What could I do (to solve this)?

(I need the position in order to retrieve the values in the col1 variable.)

Answer 1

[Joseph Cheng]

well to remedy this you shouldn't "delete" the entry of the min point but stick in a large value or Nan and use nanmin(). by deleting the minimum in the for loop you're changing the indexing positioning each time as the order of the index is different and gets shorter with each loop. force the value to be huge or nan and it'll keep the correct index for the found minimum index

[Joseph Cheng]

oh and additionally your col2(idA(i)) isn't removing duplicates its just deleted the first found min position. to delete duplicates you should use

col2(find(col2==val(i))) =nan or inf

as that'll first find the duplicate min values and sub the values

[Yan Ket]

I’m really grateful for your help.