Find max and min values, seperated by max or min

I have a large set of numbers and need to find two minimum values and two maximum values. However it shouldn't just be the two absolute max and min values they need to be seperated by a max or min value. So max,min,max,min.

Answer 1

[KSSV]

Let A be your array.

[val1,idx1] = max(A) ;
A(idx1) = NaN ;
[val2,idx2] = max(A) ; 
if idx1 > idx2 
    [val3,idx3] = min(A(idx2:idx1)) ; 
else
    [val3,idx3] = min(A(idx1:idx2)) ; 
end

[val4,idx4] = min(A(idx2:end)) ; 

Also read about findpeaks. Also you can sort array and get it.

[FV]

This works for most, but if the idx1 is ex10 and idx2 is 3 it don't work

[KSSV]

Use a if condition and change the indices....edited the answer.

[FV]

Super, But one more thing. If the two values lies beside each other. The code dosn't work so good. Can it be changed so that it do?

[KSSV]

If two values lie beside each other, will there be any value between them?

How? Can you give an example?

[FV]

no, it won't be any value between them, that's the problem. I want to exlude max values that is beside each other.

I made an example, so if A=[1;3;1.2;1.2;0.7;0.6;0.61;1;4;7;1.2;0.5]; The two max values is beside each other. I don't want that. So instead of 7 and 4 is max I want 7 and 3.

I also want the code to work if they are not beside each other. Just if the two values is next to each other I want to find the next value.

[KSSV]

clc; clear all ;
A=[1;3;1.2;1.2;0.7;0.6;0.61;1;4;7;1.2;0.5]; 
B = A ;
[val1,idx1] = max(A) ;
A(idx1) = NaN ;
[val2,idx2] = max(A) ; 
while (abs(idx1-idx2)==1)
  A(idx2) = NaN ;
  [val2,idx2] = max(A) ; 
end

if idx1 > idx2 
    [val3,idx3] = min(A(idx2:idx1)) ; 
else
    [val3,idx3] = min(A(idx1:idx2)) ; 
end

[val4,idx4] = min(A(idx2:end)) ;