[R] what "density" is plotting ?

Ralf B ralf.bierig at gmail.com
Fri Jun 25 05:20:23 CEST 2010


The density function works empirically based on your data. It makes no
assumption about an underlying distribution.

Ralf

On Thu, Jun 24, 2010 at 10:48 PM, Carrie Li <carrieandstat at gmail.com> wrote:
> Hello, Ralf,
>
> Sorry I was being clear.
> I mean probability density function
> like normal f(x)=(1/2*pi*sd )*exp(xxxx)  something like that .
> Sorry about the confusion
>
> Carrie
>
> On Thu, Jun 24, 2010 at 10:43 PM, Ralf B <ralf.bierig at gmail.com> wrote:
>>
>> Hi Carrie,
>>
>> the output is defined by you; density() only creates the function
>> which you need to plot using the plot() function. When you call
>> plot(density(x)) you get the output on the screen. You need to use
>> pdf() if you want to create a pdf file, png() for creating a png file
>> or postscript if you like ps; there are many others.
>>
>> Ralf
>>
>> On Thu, Jun 24, 2010 at 10:35 PM, Carrie Li <carrieandstat at gmail.com>
>> wrote:
>> > Hi everyone,
>> >
>> > I am confused regarding the function "density".
>> > suppose that there is a sample x of 100 data points, and
>> > plot(density(x))
>> > gives it's pdf ?
>> > or it's more like histogram only ?
>> >
>> > thanks for any answering
>> >
>> > Carrie
>> >
>> >        [[alternative HTML version deleted]]
>> >
>> > ______________________________________________
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>> > https://stat.ethz.ch/mailman/listinfo/r-help
>> > PLEASE do read the posting guide
>> > http://www.R-project.org/posting-guide.html
>> > and provide commented, minimal, self-contained, reproducible code.
>> >
>
>



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