How to interpolate if the function is not strictly monotonic increasing

Hi all

I am struggling with interpolating the Temperature from my function which reaches a constant mole fraction after a certain temperature. How can I interpolate the first temperature point at which the constant mole fraction is reached? Thanks a lot in advance!

Answer 1

[Youssef Khmou]

hi, try :

n=2;
T2=interp(T,n);
%size(T2)=n*size(T);

fine?

[Weida]

hi, thanks for the reply, i don't quite get it though...

i get a vector T2 with double the size of T, but now? why is the size... line commented?

[Youssef Khmou]

hi, just to notice that the interpolated vector has augmented size, so you need to also interpolate the "molefraction" vector n times as the first, i think this is the problem right? if its about an other issue then let me know , can you provide some data to work with,?

[Weida]

assuming n = [0.8 0.88 0.89 0.90 0.90 0.90] and T = [450 455 460 465 470 475] I want to get the first temperature where 0.90 is reached which in this case is 465 Kelvin. How can I do it?

[Youssef Khmou]

ok try :

 Index=find(n==0.90);
 T(Index(1))

[Weida]

got it now, thank you so much!!