[SOLVED] matlab help+envelope of a signal

[sayfee]

say i have signal
a=[1 1 2 3 1 2 3];

i want to plot the envelope of this signal, how to do that in matlab?
thank you in advance.

 

[_Eduardo_]

These are few points to graph a good envelope.

For a general case use the Hilbert transform.

ht = hilbert(a) ; plot(abs(ht))

 

[sayfee]

These are few points to graph a good envelope.

For a general case use the Hilbert transform.

ht = hilbert(a) ; plot(abs(ht))

the envelope isnt following the massage..can u suggest me another code which follows accurately ??
thank you for your reply

 

[_Eduardo_]

But what is the definition of envelope you use?.
When you have a few points is not as intuitive as it is in a typical AM signal

The general definition is the modulus of the analytic signal, which is the value returned by the function hilbert ()

 

[sayfee]

ok i need something like this:
i draw the picture so the lines are not strait.

 

[sayfee]

the problem is sloved,
all i have to do is

plot(a),hold on
stem(a)

thank you sir for your cooperation