Thread Subject: signal noise filtering

Dear all,
How can I filter a signal discarding noise-like values.
for example:

x= [10 10 10 200 10 10 10 ]

I would like the 200 become a 10 after filtering

doing the average I obtain something like
x=[40 40 40 40 40 40 40 ]

and doing the running average (window=3) something like
x=[10 10 76 76 76 40 40 ]

increasing too much the size of the window is deestroing all other changes in the signal in which I'm interested

"rubionelove " <rubionelove@gmail.com> wrote in message <h1d7nd$1oj$1@fred.mathworks.com>...
> Dear all,
> How can I filter a signal discarding noise-like values.
> for example:
>
> x= [10 10 10 200 10 10 10 ]
>
> I would like the 200 become a 10 after filtering
>
> doing the average I obtain something like
> x=[40 40 40 40 40 40 40 ]
>
> and doing the running average (window=3) something like
> x=[10 10 76 76 76 40 40 ]
>
> increasing too much the size of the window is deestroing all other changes in the signal in which I'm interested

Can you tell us how you define you signal in matlab?

What signal are you going to filter?

Give details pls!

"rubionelove " <rubionelove@gmail.com> wrote in message <h1d7nd$1oj$1@fred.mathworks.com>...
> Dear all,
> How can I filter a signal discarding noise-like values.
> for example:
>
> x= [10 10 10 200 10 10 10 ]
>
> I would like the 200 become a 10 after filtering
>
> doing the average I obtain something like
> x=[40 40 40 40 40 40 40 ]
>
> and doing the running average (window=3) something like
> x=[10 10 76 76 76 40 40 ]
>
> increasing too much the size of the window is deestroing all other changes in the signal in which I'm interested

What window do you have for your signal a hamming window?

I wait your response pls!

"rubionelove " <rubionelove@gmail.com> wrote in message <h1d7nd$1oj$1@fred.mathworks.com>...
> Dear all,
> How can I filter a signal discarding noise-like values.
> for example:
>
> x= [10 10 10 200 10 10 10 ]
>
> I would like the 200 become a 10 after filtering
>
> doing the average I obtain something like
> x=[40 40 40 40 40 40 40 ]
>
> and doing the running average (window=3) something like
> x=[10 10 76 76 76 40 40 ]
>
> increasing too much the size of the window is deestroing all other changes in the signal in which I'm interested

If you have the Signal Processing Toolbox then

help medfilt1

is a good place to start. It is designed specifically to deal with exactly the problem that you have illustrated.

Regards

Dave Robinson

thank you Dave, medfilt1 was really useful !
have a nice day