PDFPLOT

PDFPLOT displays a histogram of the empirical probability density function (PDF) of the input data.

Description

PDFPLOT displays a histogram of the empirical probability density function (PDF) for the data in the input array X using nbins number of bins.
If input X is a matrix, then pdfplot(X) parses it to the vector and displays PDF of all values.
For complex input X, pdfplot(X) displays PDF of abs(X).

Example:
  y = randn( 1, 1e5 );
  pdfplot( y );
  pdfplot( y, 100 );

• Acknowledgements: This submission has inspired the following:; Probability Density Function (PDF) Estimator (V3.2)
• MATLAB release: MATLAB 6.5.1 (R13SP1)

[x x]

whats the numel function?? its not specified

[sui lasiko]

excellent!

[Norbert Pierre]

Allows visualization of the data. An extremely useful utility.

[anonym anonym]

check how it works:
plot(-3:0.1:3,pdf('norm',-3:0.1:3,0,1))
hold
pdfplot(x,30)

[Li jia]

just what i want, thank you

[Jonathan Duplicy]

good job - what I need.
unbelievable it's not included in stat. toolbox

[Hong La]

Okey, i seem it to be my need but not. This is not new thing, a little simple.

[Eoin Elliffe]

It would be nice if you could do Ntigram as for pdf you generally need variable bin sizes.

[Tim Hattrell]

I don't think this calculates the correct PDF as the area under the graph is not one. Replace bar(X, N/sum(N)); with bar(X, N/sum(N)/step); to fix this.

[seema sudevan]

 

[Sean Winfree]

Yes, the fix suggested by Tim Hattrell
returns the correct pdf. Thanks Tim

[Jon Hyde]

 

[Paul Beekhuizen]

Nothing more than just a standard histogram with cleverly chosen bins. Much better techniques exist to display a pdf. On top of that, it is buggy (although this can be easily fixed by the fix proposed in one of the other reviews).

[Holger Hiebel]

As somebody other already mentioned:
Be careful, to get the real PDF estimate replace
bar(X, N/sum(N));
with
bar(X, N/sum(N)/step);

[Amit L]

 

[mathworks2011]

[f,xi] = ksdensity(X, 'npoints', 1000);