MATLAB: I wanna find variable of x-axis in plot

axisplot

Hello, I have to find variable of x-axis in plot.
My function :
T=[5 20 30 50 55];
u=[0.08 0.015 0.009 0.006 0.0055];
plot(x,y)
I need to find variable of x in T=38.

Best Answer

interp1(T, u, 38)
This requires that T is strictly increasing or strictly decreasing.