## cheby1

on 27 Feb 2012

### Kevin Holst (view profile)

Hi, I'm having problems finding something out something simple.

If I'm given this: -

```[b,a] = cheby1(8,1,0.4);
y = filter(b,a,x);
```

then what do the three digits in the brackets after 'cheby1' mean?

Also what does b, a and x mean?

Many thanks,

Tom

Matt Fig

### Matt Fig (view profile)

on 2 Nov 2012

Hi, I'm having problems finding something out something simple.

If I'm given this: -

[b,a] = cheby1(8,1,0.4); y = filter(b,a,x);

then what do the three digits in the brackets after 'cheby1' mean?

Also what does b, a and x mean?

Many thanks,

Tom

Matt Fig

### Matt Fig (view profile)

on 2 Nov 2012

Tom's question

Hi, I'm having problems finding something out something simple.

If I'm given this: -

[b,a] = cheby1(8,1,0.4); y = filter(b,a,x);

then what do the three digits in the brackets after 'cheby1' mean?

Also what does b, a and x mean?

Many thanks,

Tom

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on 27 Feb 2012

### Honglei Chen (view profile)

on 27 Feb 2012

This is clearly explained in documentation.

```doc cheby1
```

http://www.mathworks.com/help/toolbox/signal/ref/cheby1.html

x is the input signal, also see the doc

```doc filter
```