[R] Generating a vector for breaks in a histogram
Prof Brian Ripley
ripley at stats.ox.ac.uk
Thu Jul 3 16:00:07 CEST 2003
On Thu, 3 Jul 2003, michael watson (IAH-C) wrote:
> Fantastic. You're right, I was looking for seq().
> However, my plan for using it for hist() was foiled!
> I thought if I did something like:
> > b <- seq(0,500,10)
> > hist(myvble,breaks=b)
> It would bin myvble into the bins 0-50,50-100,100-150 etc and in that way I could ensure that two histograms are on the same scale with the same bins!
> I get the following error:
> Error in hist.default(Cy5, breaks = s) : some 'x' not counted; maybe 'breaks' do not span range of 'x'
> Now this makes sense of course, my bins probably DON'T span the entire
> range of X. SOOOOO I am still left with the same problem:
> 1) two variables
> 2) I want to draw histograms of both
> 3) I want them to have the SAME x-y scale on the graph
> 4) I want them to have the SAME bin range
> How do i do it? Any suggestions?
SOOOOO choose a range of breaks to span the whole range of x!
Hint: hist(c(x1, x2)) knows how to do it, and may even provide you a
suitable vector of breaks in its return value.
> -----Original Message-----
> From: Hotz, T. [mailto:th50 at leicester.ac.uk]
> Sent: 03 July 2003 14:16
> To: michael watson (IAH-C); r-help at stat.math.ethz.ch
> Subject: RE: [R] Generating a vector for breaks in a histogram
> Dear Mick,
> Have a look at ?seq - seq(1,20,length=20) should do it.
> Thomas Hotz
> Research Associate in Medical Statistics
> University of Leicester
> United Kingdom
> Department of Epidemiology and Public Health
> 22-28 Princess Road West
> LE1 6TP
> Tel +44 116 252-5410
> Fax +44 116 252-5423
> Division of Medicine for the Elderly
> Department of Medicine
> The Glenfield Hospital
> LE3 9QP
> Tel +44 116 256-3643
> Fax +44 116 232-2976
> > -----Original Message-----
> > From: michael watson (IAH-C) [mailto:michael.watson at bbsrc.ac.uk]
> > Sent: 03 July 2003 14:02
> > To: 'r-help at stat.math.ethz.ch'
> > Subject: [R] Generating a vector for breaks in a histogram
> > Hi
> > I have two lots of numbers which I would like to histogram
> > using the hist() function. For comparative reasons, I want
> > them to be on the same scale, which I can use the xlim and
> > ylim options to achieve.
> > However, having them on the same scale is meaningless unless
> > they have the same "breaks". Consulting the documentation,
> > there are 4 ways of defining the number of breaks, only one
> > of which is "definite", the others merely form suggestions,
> > which I have found is not good enough.
> > The only definite way is to provide a vector to the hist()
> > function which is a vector of the break points for the
> > histogram. So I need to generate a vector that contains say,
> > 500, numbers in it, equi-distance apart between a min and a max. EG:
> > > myfunc(n=20,min=1,max=20)
> > would provide a vector, length 20, with the numbers 1 through
> > 20 in it.
> > Is there a function in R that can do this?
> > Thanks
> > Mick
> > ______________________________________________
> > R-help at stat.math.ethz.ch mailing list
> > https://www.stat.math.ethz.ch/mailman/listinfo/r-help
> R-help at stat.math.ethz.ch mailing list
Brian D. Ripley, ripley at stats.ox.ac.uk
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595
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