How to divide a signal to a function?

Hi dear friends. I have a nonstationary signal and I want to divide it to a 4-order polynomial function. but the result doesn't seem correct:

I simply do it like :

w= signal./function

Here's the signal plot:

this is the function:

and the result (when I divide them) is this:

I don't know what that big peak is? Logcally it shouldn't seem like this and should be like a stationary signal

I would be so garteful if you guide me

Answer 1

[Chunru]

The "function" has a value close to 0 and thus division by 0 (or small value) results in the big peak.

[Fatemeh Sharafi]

Then I think I should delete that portion from the function. Thanks

[Chunru]

It depends on what you want to do, which you did not explain clearly. Anyway you should always avoid the division by zero. You many consider the following:

w= signal./ (f+0.5);        % don't use function as variable name

[Fatemeh Sharafi]

this function was obtained from curve fitting the 4th-order polynomial func to a non-statinary signal. Then I used the fit function to convert the nonstationary signal to stationary by divide them.

thanks by the way. Your help was perfect