I have an experimentally determined curve (a xy graph) where x is almost equal to y (but not really equal). This graph was built by experimental measurements point after point (x in function of y). X is not exactly equal to y because of physical properties of device. In my project I have to add little software offsets (negative and positive numbers) in order to have x=y for each x (a lot of measured values..around 100, 200..it depends). All this offsets I have put in an EEPROM memory which is limited.

My question is: Is there any possibility to build a function (polynomial) based on all these number of offsets in order to put in my memory only the coefficients of the polynomial (which are a smaller number)? How?

Thank you very much!