X = normrnd(0,1,10,1)
Y = 1+0.2*X
% sort:
[Xs,idx] = sort(X);
Ys = Y(idx);
% interpolate:
Xo = [0.001,1.89,-0.45,1.12];
Yo = interp1(X,Y,Xo)
Note that you will need to explicitly specify the behavior if you want it to extrapolate as well as interpolate. You can also choose the interpolation method. Read the documentation to know more.
