[R] histogram

David Winsemius dwinsemius at comcast.net
Tue Feb 7 00:18:57 CET 2012


On Feb 6, 2012, at 5:26 PM, Francis Keyes wrote:

> Hi David,
>
> I have 2 tables, each with several columns and rows of data.  I am
> only interested in the data from column 6, which contains values in
> the range -PI to PI.  I want to plot the data from tableD with the y
> axis denoting percentage with respect to tableR.  So if data points in
> the break 2 - 3 appear half as often in tableD as in tableR, the y
> axis should show 50 percent.  Does that make sense?
> I've been plotting the data like this to date:
>
> hist(tableD[,6],ylab="frequency", xlab="angle")

It all makes sense, (and it made sense before) , but your  
responsibility is to provide data.

(Contrats on plain text lesson successfully met.)

>
> Thanks a lot for your help
>
>
>
> On Mon, Feb 6, 2012 at 1:31 PM, David Winsemius <dwinsemius at comcast.net 
> > wrote:
>>
>>
>> On Feb 6, 2012, at 12:23 PM, Francis Keyes wrote:
>>
>>> Thanks.  How do you suggest I use the reference population?   
>>> Sorry, I'm new to R and just don't see it.  If i can get a plot  
>>> that is counts or density relative to my reference data it would  
>>> be ideal.
>>
>>
>> It is difficult to specify "how" when we have no "what". The "what"  
>> is your responsibility, not ours. My thought was to use the ratio  
>> of the results of hist() on the two populations  which would then  
>> be offered back to hist or barplot. ....which (of course) requires  
>> that the 'breaks'  be the same. Provide an example of your R  
>> representations of the reference population and tested population  
>> and all will become clear.
>>
>> (And learn to post in plain text, please.)
>>
>> --
>> David Winsemius, MD
>> West Hartford, CT
>>>
>>>
>>> On Mon, Feb 6, 2012 at 1:12 AM, David Winsemius <dwinsemius at comcast.net 
>>> > wrote:
>>>
>>> On Feb 5, 2012, at 8:31 PM, Francis Keyes wrote:
>>>
>>> With R and the hist function, is there a way to make a histogram  
>>> in which
>>> the y axis denotes propotion with respect to a separate sample  
>>> dataset of
>>> the same range instead of frequency?
>>>
>>> hist() returns an object with both "counts" and "density". If you  
>>> had a reference population it should be a fairly simple matter to  
>>> use one or the other of those.
>>>
>>
>>
>>
>>
>>

David Winsemius, MD
West Hartford, CT



More information about the R-help mailing list