[R] Question about histogram

[Jonathan P Daily]

Because a histogram is descriptive and makes no assumptions about what it 
describes? Attaching a probability to the bars assumes that some random 
draw is being made. Suppose my data is a count of computers running a 
particular OS. What would be the value in reporting this as a probability 
that a randomly chosen computer is running Ubuntu? Density is more 
universal, IMO.
--------------------------------------
Jonathan P. Daily
Technician - USGS Leetown Science Center
11649 Leetown Road
Kearneysville WV, 25430
(304) 724-4480
"Is the room still a room when its empty? Does the room,
 the thing itself have purpose? Or do we, what's the word... imbue it."
     - Jubal Early, Firefly

r-help-bounces at r-project.org wrote on 01/13/2011 01:37:01 PM:

> [image removed] 
> 
> [R] Question about histogram
> 
> Longe 
> 
> to:
> 
> r-help
> 
> 01/13/2011 03:11 PM
> 
> Sent by:
> 
> r-help-bounces at r-project.org
> 
> Dear list,
> 
> I'm new to R, please bear with my silly questions.  I'm trying to get an 

> understanding of why the results I get from a call to hist() are not as 
> I thought I would get.  When I use the parameter freq=FALSE, I think the 

> plot will contain bars that none of them is larger than 1, because 
> they're probabilities.  But for my code, the bars exceeded 1.
> 
> The actual data seems immaterial.  I tried with dummy data:
> 
>  > hist(runif(1000), freq=FALSE)
> 
> and the histogram includes bars well over 1 in height.  The man page 
> says that freq=FALSE produces densities, so that the total area is 1. 
> Clearly if all the values are between 0 and 1, as is the case here, some 

> of the bars stand out above 1, for the area to be 1.  I thought that it 
> is the sum of the bar heights that would be 1, so that the bars reflect 
> probabilities for each interval, rather than densities.  So, the answer 
> to my question would be "because it's densities, not probabilities", but 

> then the question is, why densities and not probabilities?
> 
> Regards,
> L.
> 
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