curve fitting, can anybody fit data and find out relation between x and y

I need to know relation between x and y. anybody suggest please curve fitting code

x = [54 55 56 57 58 59 60 63 65 71 73 74 75 76 77 78 79 80];

y=[0.0600 0.5300 0.1500 0.0995 0.0559 0.0500 0.0200 0.0100 0.3000 0.1500 0.0500 0.0680 0.0980 0.0500 0.0500 0.1400 0.1400 0.1580];

I am interested in inverse relation? regards

[Star Strider]

What process produced those data?

Do you have a mathematical model for that process?

Answer 1

[John D'Errico]

You are the 1 millionth person to ask this question. No prize is awarded though. Sorry.

plot(x,y,'o-')

What makes you think there is some relationship between x and y? You want to compute the inverse function. For any given value of y, which of the several values of x should an inverse return?

The fact is, there are infinitely many possible functions that will reproduce this data. None of them will be invertible though.

You might decide to approximate the data by some simple model. It probably won't be invertible either though, except for polyfit, using at most a simple straight line model.