Is there a way to plot a frequency histogram from a continuous variable?

Question

I have DNA segment lengths (relative to chromosome arm, 251296 entries), as such:

The range goes from 0 to 2, and I would like to make a continuous relative frequency plot. I know that I could bin the values and use a histogram, but I would like to show continuity. Is there a simple strategy? If not, I'll use binning. Thank you!

EDIT:

I have created a binning vector with 40 equally spaced values between 0 and 2 (both included). For simplicity's sake, is there a way to round each of the 251296 entries to the closest value within the binning vector? Thank you!

When you say "continuous relative frequency plot" do you mean that some of your 251,296 entries are duplicated and you want this frequency to be plotted on the y-axis? — Nathan S. Watson-Haigh, May 12 '15 at 03:19
Use a kernel density plot. There are a few ways to do that in R (or any other software) if you look it up. — Frank, May 12 '15 at 03:20
@NathanS.Watson-Haigh Hi! I mean that the values come from a continuous variable. There may be some duplicates. :) — Johnathan, May 12 '15 at 03:24

Nathan S. Watson-Haigh · Answer 1 · 2015-05-12T03:42:41.163

3

Given that most of your values are not duplicated and thus don't have an easy way to derive a value for plotting on the y-axis, I'd probably go for a density plot. This will highlight dense segment lengths i.e. where you have lots of segment lengths occurring near each other.

d <- c(0.24592963, 0.08555043, 0.02128725)
plot(density(d), xlab="DNA Segment Length", xlim=c(0,2))

enter image description here

edited May 12 '15 at 03:42

answered May 12 '15 at 03:34

Nathan S. Watson-Haigh

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Hi! Thank you for your quick response. I did it and it looks nice. However, I would like some segments near the value to show up. So, I think that I use relative histogram AND plot the density function. – Johnathan May 12 '15 at 03:37

Is there a way to plot a frequency histogram from a continuous variable?

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