[R] overlaying frequency histograms or density plots in R

Bogdan Tanasa
Thu, 25 Feb 2021 07:43:09 -0000

Thanks a lot Petr !

shall i uses "dodge" also for the RELATIVE FREQUENCY HISTOGRAMS :

p <- ggplot(iris, aes(x=Sepal.Length, y=..count../sum(..count..)*100,
colour=Species))
p+geom_histogram(position="dodge")

or is there any other way to display the RELATIVE FREQUENCY HISTOGRAMS ?

thanks again !

On Wed, Feb 24, 2021 at 11:00 PM PIKAL Petr <petr.pikal at precheza.cz>
wrote:

> Hi
>
> You should use position dodge.
>
> p <- ggplot(iris, aes(x=Sepal.Length, colour=Species))
> p+geom_density()
> p <- ggplot(iris, aes(x=Sepal.Length, y=..density.., colour=Species))
> p+geom_histogram(position="dodge")
>
> Cheers
> Petr
> > -----Original Message-----
> > From: R-help <r-help-bounces at r-project.org> On Behalf Of
Bogdan Tanasa
> > Sent: Wednesday, February 24, 2021 11:07 PM
> > To: r-help <r-help at r-project.org>
> > Subject: [R] overlaying frequency histograms or density plots in R
> >
> > Dear all, we do have a dataframe with a FACTOR called EXP that has 3
> LEVELS ;
> >
> >  head(pp_ALL)
> >     VALUE  EXP
> > 1 1639742 DMSO
> > 2 1636822 DMSO
> > 3 1634202 DMSO
> >
> > shall i aim to overlay the relative frequency histograms, or the
density
> > histograms for the FACTOR LEVELS,
> >
> > please would you let me know why the following 2 pieces of R code show
> > very different results :
> >
> > ggplot(pp_ALL, aes(x=VALUE, colour=EXP)) + geom_density()
> >
> > versus
> >
> > ggplot(data=pp_ALL) +
> >        geom_histogram(mapping=aes(x=VALUE, y=..density.., colour=EXP),
> >  bins=1000)
> >
> > thanks,
> >
> > bogdan
> >
> > ps : perhaps i shall email to the folks on ggplot2 mailing list too
...
> >
> >       [[alternative HTML version deleted]]
> >
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>

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