[R] use different symbols for frequency in a plot

[Kerry Bush]

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?
> > 
> > ______________________________________________
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> > 
> 
>