[R] use different symbols for frequency in a plot

[Adaikalavan Ramasamy]

Remove the '6' from the code that contains 'cut'. I am not sure how it
crept into my code. Then you should have the following mapping

	Freq	pch code
	1-5	1
	6-10	2
	11-	3

I am more concerned about viewers getting confused with many symbols
than running out of symbols in R. Looking at the last example in
help("points"), I would say that there are 20-30 usable symbols.
Remember that you can also use text() to put multi-character text.

Regards, Adai



On Mon, 2005-08-08 at 13:42 -0700, Kerry Bush wrote:
> Thank you.
> 
> But I only need three classes of freqnencies (in
> another words, only three kinds of symbols) for 1-5,
> 5-10 and above 10, not to use different symbols for
> different frequencies. Otherwise, clearly R will run
> out of available symbols and the plot is also hard to
> view.
> 
> Thank you anyway.
> 
> --- Adaikalavan Ramasamy <ramasamy at cancer.org.uk>
> wrote:
> 
> > Group by which variable ? If you mean the joint
> > distribution of 'x' and
> > 'y' then something along the following lines
> > 
> >  x <- rep( c(0.1, 0.2, 0.4, 0.5),      c(5, 6, 10,
> > 20) )
> >  y <- rep( c(0.5, 0.6, 1.2, 2.5, 3.0), c(3, 8, 8,
> > 18, 4) )
> > 
> >  new     <- factor( paste(x, y, sep="_") )
> >  tb      <- table(new)
> > 
> >  pchcode <- cut(tb , c(-Inf, 1, 5, 6, 10, Inf),
> > labels=F)
> > 
> >  tmp     <- t( sapply( strsplit( names(tb),
> > split="_") , c ) )
> >  df      <- data.frame( x=tmp[ ,1], y=tmp[ ,2], 
> >                         freq=as.vector(tb), pchcode
> > = pchcode -1 )
> > 
> >      x   y freq pchcode
> >  1 0.1 0.5    3       1
> >  2 0.1 0.6    2       1
> >  3 0.2 0.6    6       2
> >  4 0.4 1.2    8       3
> >  5 0.4 2.5    2       1
> >  6 0.5 2.5   16       4
> >  7 0.5   3    4       1
> > 
> > And now to plot it, we use points() repeatedly.
> > 
> >  plot( as.numeric(df$x), as.numeric(df$y), type="n"
> > )
> > 
> >  for( i in unique( df$pchcode ) ){
> >     w <- which( df$pchcode == i )
> >     points( df$x[w], df$y[w], pch=as.numeric(i) )
> >  }
> > 
> > I am sure someone else will come up with a neater
> > solution.
> > 
> > 
> > Can I also suggest that you try the following
> > 
> >   plot( jitter(x), jitter(y) )
> > 
> > or better still the following
> > 
> >   library(hexbin)
> >   plot( hexbin(x, y) )
> > 
> > 
> > Regards, Adai
> > 
> > On Mon, 2005-08-08 at 11:57 -0700, Kerry Bush wrote:
> > > suppose I have the following data
> > > 
> > > x<-c(rep(.1,5),rep(.2,6),rep(.4,10),rep(.5,20))
> > >
> >
> y<-c(rep(.5,3),rep(.6,8),rep(1.2,8),rep(2.5,18),rep(3,4))
> > > 
> > > If I plot(x,y) in R, I will only get seven
> > distinct
> > > points. What I want to do is to use different
> > symbols
> > > to show the frequency at each point.
> > > 
> > > e.g. if the frequncey is between 1 and 5, then I
> > plot
> > > the point as a circle; if the frequency is between
> > 6
> > > and 10, then I plot the point as a square; if the
> > > frequency is above 10, then I plot the point as a
> > > triangle.
> > > 
> > > I am not sure how to do this in R. Can anybody
> > help me?
> > > 
> > > ______________________________________________
> > > R-help at stat.math.ethz.ch mailing list
> > > https://stat.ethz.ch/mailman/listinfo/r-help
> > > PLEASE do read the posting guide!
> > http://www.R-project.org/posting-guide.html
> > > 
> > 
> > 
> 
> 
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