Find X of corresponding Y which is manipulated?

i need to extract the exact values where the increasing and decreasing trend starts.

I have Fx (column vector) and corresponding T values (column vector). step 1: the values which are less than 100, converts into 0

Fx(Fx <100)= 0;

step2: Fx(diff(Fx)==0) = []; % delete the element which is repeating

step3:B = [0; diff(Fx)]; %difference between element It will start with the first element in the matrix and then report the difference between that and the next element. There's no leading element before the first one so is just truncates the matrix by one element. We add a zero because there is no change there as it's the starting element.

step4: Result = find(B(1:end-1).*B(2:end)<0); This will return the index where you are on the cusp of the inflection. In this case it will be.

step5: New_Fx=Fx(Result); gives the Fx values where trends get changed

Now how to find corresponding T values? I tried New_T=T(New_Fx); but not it showing wrong T values. I think we have removed the elements in Fx which are repeating but not corresponding T values.

How to find these T values to corresponding New_Fx?

complete code is: Fx(Fx <100)= 0;

Fx(diff(Fx)==0) = [];

B = [0; diff(Fx)]; Result = find(B(1:end-1).*B(2:end)<0); New_Fx=Fx(Result);

Answer 1

[Andrei Bobrov]

[~,i1] = findpeaks(Fx);
[~,i2] = findpeaks(-Fx);

out = T(sort([i1;i2]));

without findpeaks:

ll = find([true;diff(Fx)~=0]);
F = Fx(ll);
b = diff(F);
lll = [false;b(1:end-1).*b(2:end)<0;false];
out = T(ll(lll));

ADD

complete code:

x = xlsread('book3.xlsx');
xx = x(:,2);
xx(xx <100)= 0;
[~,i1] = findpeaks(xx);
[~,i2] = findpeaks(-xx);
out = x(sort([i1;i2]),1);

[Sagar Dhage]

Thanks Andrei for your effort. But it not working properly. I am attaching data file and script file.

 complete code is:

x=xlsread('book3.xlsx'); save book3.mat x; load book3 T=x(:,1); Fx_all=x(:,2);

Fx=Fx_all;

Fx(Fx <100)= 0;

Fx(diff(Fx)==0) = [];

B = [0; diff(Fx)]; Result = find(B(1:end-1).*B(2:end)<0); New_Fx=Fx(Result);

[~,i1] = findpeaks(New_Fx); [~,i2] = findpeaks(-New_Fx); out = T(sort([i1;i2]));

[Andrei Bobrov]

see my answer after 'ADD'