How can I do high pass filter to a curve ?

Hello

How can I do high pass filter to this curve ?

[Jan]

By using a high pass filter? But there is an infinite number of different filters and the readers cannot guess, what you exactly needs.

[Mallouli Marwa]

I want to reduce the noise to obtain a curve like this as attached.

[Jan]

We cannot know which frequencies are the wanted signal and what you consider to be noise. The definition of "noise" depends an what you want to measure.

[Mallouli Marwa]

The wanted frequency is 29.22 Hz

[Jan]

If you filter away everything different from the wanted frequency, you get a sharp peak - but this will happen for pure noise also. So except the wanted frequency, you need to define, what is considered as noise - preferably based on a physical analysis of what is causing the noise.

[Mallouli Marwa]

So on Matlab, I can't delete this noise ?

[Jan]

Again: Which noise? Of course you can delete everything except for the wanted 29.22 Hz, but then your signal has no information anymore. What is is spectrum of the noise you want to suppress?

[Anton Semechko]

By the way, just by looking at the sample voltage vs. frequency plot (Al_analytical_model.jpeg), it is obvious that low frequencies dominate the signal. If that plot is a reflection of the the signal you want to recover, are you sure you want to use a high-pass filter and not a low-pass filter?

[Mallouli Marwa]

I'm not sure.

Just I want a perfect curve without noise like the attached.

For a freq of 30Hz I can't delete noise ?

[Jan]

"I just want a perfect curve" does not allow the readers to help you.

[Mallouli Marwa]

These are the program developed and the input data.

How can I ameliorate this program and fit the curve or eliminate the noise ?