I am a regular user of Origin and have used several unique functions for fitting with in the past.
Today I have tried to fit a very simple function; however just can not get it to work. I have a data set to which I am trying to fit the function P = B * cos(x)^2
(NOTE: just to make clear that this is a cos squared term)
P is what I measure; B is a fixed parameter or constant to be evaluated by fitting; and x is what I measure.
You need revise your fitting function as below: P=A*cos((x-40)*pi/180)^2
As we know, cos(90°)=0. In you experiential data, when X=130, Y is close to 0. So you need add a X offset(about 40 here) on your fitting function. Then you need convert X values in degree to radians values by multiplying by pi/180.
trouble fitting simple function y=B*(cos(x))^2
Posted - 01/11/2016 : 4:28:59 PM
