How to draw probability density function in MatLab?

Question

x = [1 2 3 3 4]
cdfplot(x)

After Googling, I find the above code will draw a cumulative distribution function for me in Matlab.
Is there a simp

Answer 1

type "ksdensity" in matlab help and you will find out the function that will give you the continuous form of PDF. I guess this is exactly what you are looking for.

Answer 2

If you want a continuous distribution function, try this.

x = [1 2 3 3 4]
subplot(2,1,1)
ksdensity(x)
axis([-4 8 0 0.4])

subplot(2,1,2)
cdfplot(x)
grid off
axis([-4 8 0 1])
title('')

Which outputs this.

The Cumulative Distribution Function is on the bottom, the Kernel Density Estimate on the top.

Answer 3

In addition to the smooth PDF obtained by ksdensity(x), you can also plot a smooth CDF plot using ksdensity(x,'function','cdf').

Answer 4

You can generate a discrete probability distribution for your integers using the function hist:

data = [1 2 3 3 4];           %# Sample data
xRange = 0:10;                %# Range of integers to compute a probability for
N = hist(data,xRange);        %# Bin the data
plot(xRange,N./numel(data));  %# Plot the probabilities for each integer
xlabel('Integer value');
ylabel('Probability');

And here's the resulting plot:

---

UPDATE:

In newer versions of MATLAB the hist function is no longer recommended. Instead, you can use the histcounts function like so to produce the same figure as above:

data = [1 2 3 3 4];
N = histcounts(data, 'BinLimits', [0 10], 'BinMethod', 'integers', 'Normalization', 'pdf');
plot(N);
xlabel('Integer value');
ylabel('Probability');