MATLAB Central Newsreader - How to detect pulse signal overlap?

How to detect pulse signal overlap?

Wes — Wed, 21 Oct 2009 00:22:04 -0400

I have each huge square pulse signal data from two channels. In the following oversimplified example, how can I detect which pulse events are overlapped between channel A and channel B?

% column 1 is time; column 2 is volt
pulseA(:,1) = [0:10];
pulseA(:,2) = [0 0 5 5 0 0 0 0 0 0 0];
pulseB(:,1) = [0:10];
pulseB(:,2) = [0 5 5 5 5 0 0 5 5 0 0];
plot(pulseA(:,1),pulseA(:,2),'b')
hold on
plot(pulseB(:,1),pulseB(:,2),':r')

Thanks

Re: How to detect pulse signal overlap?

ImageAnalyst — Wed, 21 Oct 2009 02:14:52 -0400

On Oct 20, 8:22 pm, "Wes" <wspar...@hotmail.com> wrote:
> I have each huge square pulse signal data from two channels. In the following oversimplified example, how can I detect which pulse events are overlapped between channel A and channel B?
>
> % column 1 is time; column 2 is volt
> pulseA(:,1) = [0:10];
> pulseA(:,2) = [0 0 5 5 0 0 0 0 0 0 0];
> pulseB(:,1) = [0:10];
> pulseB(:,2) = [0 5 5 5 5 0 0 5 5 0 0];
> plot(pulseA(:,1),pulseA(:,2),'b')
> hold on
> plot(pulseB(:,1),pulseB(:,2),':r')
>
> Thanks

-----------------------------------------------------------------------
As long as the first columns refer to the same x coordinates you can
do this:
overlap = (pulseA(:,2) == pulseB(:, 2););

Re: How to detect pulse signal overlap?

Wes — Wed, 21 Oct 2009 11:37:05 -0400

ImageAnalyst <imageanalyst@mailinator.com> wrote in message <4455e2d5-5f9f-4d01-8980-1348163c8d0c@a6g2000vbp.googlegroups.com>...
> On Oct 20, 8:22?pm, "Wes" <wspar...@hotmail.com> wrote:
> > I have each huge square pulse signal data from two channels. ?In the following oversimplified example, how can I detect which pulse events are overlapped between channel A and channel B?
> >
> > % column 1 is time; column 2 is volt
> > pulseA(:,1) = [0:10];
> > pulseA(:,2) = [0 0 5 5 0 0 0 0 0 0 0];
> > pulseB(:,1) = [0:10];
> > pulseB(:,2) = [0 5 5 5 5 0 0 5 5 0 0];
> > plot(pulseA(:,1),pulseA(:,2),'b')
> > hold on
> > plot(pulseB(:,1),pulseB(:,2),':r')
> >
> > Thanks
>
> -----------------------------------------------------------------------
> As long as the first columns refer to the same x coordinates you can
> do this:
> overlap = (pulseA(:,2) == pulseB(:, 2););

Sorry that I oversimplified my example. What if the first column data between channel A and channel B are not same? For example, if pulseB(:,1) = [0 0.9 1 2.2 3 7 7.1 7.2 8 9 9.5]. Thanks again!

Re: How to detect pulse signal overlap?

Lars — Wed, 21 Oct 2009 14:08:19 -0400

how about something like

% pseudocode

find(a) && find(b)

% or

a(a~=0) && b(b~=0)

you can see it as a modified form of a phase locked loops phase diskriminator

Lars

Re: How to detect pulse signal overlap?

ImageAnalyst — Wed, 21 Oct 2009 17:35:18 -0400

Maybe you should first use interp1() to get a common x axis.
Otherwise, being digital there's no certain way to tell overlap unless
you make assumptions. For example if A=5 and 1 and 5 at 2, while B =
5 at 0.9 and still 5 at 2.1, can you say that B = 5 at 1 and 2? No,
you can't because you don't have B measured at those locations. You
can make some guess at what B would be there (for example using
interp1) and then you can make the comparison. Also, what does
overlap mean? Do they need to have the same Y value? What if, at a
particular X, A equaled 5 and B equaled 4. Is that an overlap
condition?