Low Pass filter on a digital signal in matlab

I am new to using matlab and signal processing in general and can't figure out how to implement a low pass filter. I have these digital signal that's a vector and would like to run it through a low pass fiter of 40hz or if at all possibl开发者_如何学Goe a bandpass filter .53-40hz (12db/oct). I have access to the signal processing toolbox but can't figure out how. Any help is appreciated.

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There is more then one option to applying a digital filter in Matlab. The doc is very good, so it is a good starting point to look at it and follow the examples:

1. Applying 1D digital filter
2. Using conv for filtering using a FIR filter
3. FIR filter design
4. IIR filter design