Graph non-linearity calculation

[thavamaran]

linearity calculation

Hi guys, im currently undergoing process of my final engineering project. so im analyzing my sensor via graph. so i have attach two graph image whereby i need to compare the actual output which is in blue line and red line is the actual linearity graph which how it suppose to be. so now i need to find the drifting percentage between the actual graph and the linearity graph. i need idea how to do it, can anyone guide me through please. thank you.

in second graph i have pointed out the drifted point from linearity form. please guide me through.

 

[kender]

linearity graph

If you want to know which graph fits the the theoretical data better, you might be able to use the R².
Although overall, I'm not clear as to what you want to accomplish.