Hello! Socratic's Terms of Service and Privacy Policy have been updated, which will be automatically effective on October 6, 2018. Please contact hello@socratic.com with any questions.

What is the difference between a discrete uniform distribution and a continuous uniform distribution?

1 Answer
May 18, 2015

One way of knowing discrete or continuous is that in the case of discrete a point will have mass, and in continuous a point has no mass.

this is better understood when observing the graphs.

Let us look at the Discrete first.

Take a look at its pmf

enter image source here

notice how the mass is sitting on the points?

now look at its cdf

enter image source here

notice how the values go up in steps, and that the line is not continuous? this also shows how there is mass at the point on the pmf

Now we will look at the Continuous case

observe its pdf

enter image source here

notice how mass is not sitting at a point, but between two points?

and now to look at the cdf

enter image source here

here you can see on the cdf that the function is continuous, is does not go in steps that that on the discrete case.

I had pulled these images of wikipedia, so here is the reference to the pages, where you could also read up a bit more on the topics.

Discrete uniform distribution

Continuous uniform distribution