>I'd say you should scale the height such that the sum of the bins
>come out to 1. Basically you scale it such that it becomes a
>probability density estimate.
>
Hi All
Sorry to ask this damn thing again but I just need some confirmation.
I am not convinved with the solution that to normalize the histogram
(y-axis in terms of pdf) the sum of all bins has to be 1.
example: for Normal Distribution,
N=1e6;
x=randn(1,N);
[N1 X1]=hist(x,100); % 100 bins
subplot(211)
plot(X1,N1/sum(N1))
will have different solution when number of bins increase
[N2 X2]=hist(x,200);
subplot(212)
plot(X2,N2/sum(N2))
but I think it should be
figure
[N3 X3]=hist(x,100);
subplot(211)
plot(X3,1/(sqrt(2*pi)*std(x))*N3/max(N3))
[N4 X4]=hist(x,200);
subplot(212)
plot(X4,1/(sqrt(2*pi)*std(x))*N4/max(N4))
I might be wrong but it will be really great if anybody can throw light on
this.
Chintan
Reply by cpshah99●June 25, 20092009-06-25
>I'd say you should scale the height such that the sum of the bins
>come out to 1. Basically you scale it such that it becomes a
>probability density estimate.
>
Hi Julius
Thanks as always for your reply.
So, if there are 100 bins, then sum of these 100 bins should be equal to
1.?
Will this give me the y-axis to be p(\hat{x}/x) where \hat{x} is o/p of
equalizer and x is transmitted symbols?
Thanks again.
Chintan
Reply by julius●June 25, 20092009-06-25
On Jun 25, 10:42�am, "cpshah99" <cpsha...@rediffmail.com> wrote:
> Dear All
>
> I am trying to plot histogram of the o/p of equalizer. As the o/p is
> complex I will have to plot histogram of real and imaginary part
> separately. I know it is straight forward in matlab, but the problem is how
> to normalize y-axis.
>
> The modulation I am using is 4-QAM. As this will be bimodal distribution
> around +1 and -1, I am thinking to do following:
>
> 1. find std deviation (\sigma) of real(x_hat)>0 (which should be equal to
> std deviation of real(x_hat)<0).
>
> 2. Nromalize the histogram between 0 and 1 and then scale it again with �
> 1/(sigma*sqrt(2*pi)).
>
> Is this correct? or any other way to do it?
>
> Your opinion matters a lot.
>
> Thanks
>
> Best Regards,
>
> Chintan
I'd say you should scale the height such that the sum of the bins
come out to 1. Basically you scale it such that it becomes a
probability density estimate.
Reply by cpshah99●June 25, 20092009-06-25
Dear All
I am trying to plot histogram of the o/p of equalizer. As the o/p is
complex I will have to plot histogram of real and imaginary part
separately. I know it is straight forward in matlab, but the problem is how
to normalize y-axis.
The modulation I am using is 4-QAM. As this will be bimodal distribution
around +1 and -1, I am thinking to do following:
1. find std deviation (\sigma) of real(x_hat)>0 (which should be equal to
std deviation of real(x_hat)<0).
2. Nromalize the histogram between 0 and 1 and then scale it again with
1/(sigma*sqrt(2*pi)).
Is this correct? or any other way to do it?
Your opinion matters a lot.
Thanks
Best Regards,
Chintan