Re: [R] plotting every ith data point?

From: Greg Snow <Greg.Snow_at_imail.org>
Date: Fri, 22 Feb 2008 12:37:54 -0700

Just to give you more options to choose from,

Here is a variation on Gabor's solution:

 with(example.df[c(TRUE,FALSE,FALSE,FALSE,FALSE),], {    plot(DSR1 ~ StartDate, type = "b", ylim = c(0.3, 0.9))    points(DSR2 ~ StartDate, type = "b", pch = 3)  })

Move the TRUE around and you get the different sequences and you don't need to know the number of rows.

On a similar note you could try:

plot(DSR1 ~ StartDate, type='b', ylim=c(0.3,0.9), pch=c(1,rep(NA,4))) points(DSR2 ~ StartDate, type='b', pch=c(3,rep(NA,4)))

You will still have the lines between all the points, but only every 5th point.

Hope this helps,

-- 
Gregory (Greg) L. Snow Ph.D.
Statistical Data Center
Intermountain Healthcare
greg.snow_at_imail.org
(801) 408-8111
 
 


> -----Original Message-----
> From: r-help-bounces_at_r-project.org
> [mailto:r-help-bounces_at_r-project.org] On Behalf Of Jessi Brown
> Sent: Wednesday, February 20, 2008 6:57 PM
> To: Gabor Grothendieck
> Cc: r-help_at_r-project.org
> Subject: Re: [R] plotting every ith data point?
>
> Thanks for the ideas so far, Gabor and Phil.
>
> I was hoping to find a solution that didn't depend on
> building another data frame, but if that's the easiest way, I
> can certainly do it through that route. At least your
> solutions involve fewer lines of code than I had devised for
> extracting the desired rows (am still a newbie at data
> manipulation with R!).
>
> cheers, Jessi
>
> On Wed, Feb 20, 2008 at 7:08 PM, Gabor Grothendieck
> <ggrothendieck_at_gmail.com> wrote:
> > Try this:
> >
> > ix <- seq(1, nrow(example.df), 5)
> > with(example.df[ix,], {
> > plot(DSR1 ~ StartDate, type = "b", ylim = c(0.3, 0.9))
> > points(DSR2 ~ StartDate, type = "b", pch = 3)
> > })
> >
> >
> >
> >
> > On Wed, Feb 20, 2008 at 6:57 PM, Jessi Brown
> <jessilbrown_at_gmail.com> wrote:
> > > Hello, fellow R enthusiasts.
> > >
> > > Ok, I've been racking my brain about this small issue,
> and between
> > > searching the help archives and reading through the
> plot-related >
> > documentation, I can't figure out how to achieve my desired
> endpoint
> > > without some ugly, brute force coding.
> > >
> > > What I would like to do is make a plot in which only a
> subset of my
> > > data are plotted, but in regular intervals, such as every
> 5th point
> > > along the sequence. Is anyone aware of a built-in
> function in plot
> > or > a related graphing family that can do this, or
> alternatively, a
> > simple > way to extract the desired rows from my original
> dataframe?
> > I want to > do this because I want to plot multiple series
> of points
> > with their > confidence intervals (arrows), and even if I specify
> > type="b," the > output ends up looking like just a series
> of crowded points.
> > >
> > > For example, if you try making the plot below, you will
> see how >
> > crowded two lines look without error bars:
> > >
> > > > example.df<-data.frame(StartDate=(94:157), DSR1=seq(0.4, 0.8,
> > length.out=64), DSR2=seq(0.3, 0.9, length.out=64)) > >
> > plot(example.df$StartDate, example.df$DSR1, type="b",
> ylim=c(0.3,0.9))
> > > > points(example.df$StartDate, example.df$DSR2, type="b",
> pch=3) >
> > > Any ideas for an elegant solution to my dilemma?
> > >
> > > Thanks in advance for any help.
> > >
> > > cheers, Jessi Brown
> > >
> > > Ph.D. student
> > > Program in Ecology, Evolution, and Conservation Biology >
> > University of Nevada, Reno > >
> > ______________________________________________
> > > R-help_at_r-project.org mailing list
> > > 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.
> > >
> >
>
> ______________________________________________
> R-help_at_r-project.org mailing list
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> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
______________________________________________ R-help_at_r-project.org mailing list 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.
Received on Fri 22 Feb 2008 - 19:41:04 GMT

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