[R] Continuous legend colors

[Tim Clark]

Thanks Jim, that is exactly what I was looking for!

Tim


Tim Clark
Department of Zoology 
University of Hawaii


--- On Sun, 11/29/09, Jim Lemon <jim at bitwrit.com.au> wrote:

> From: Jim Lemon <jim at bitwrit.com.au>
> Subject: Re: [R] Continuous legend colors
> To: "Tim Clark" <mudiver1200 at yahoo.com>
> Cc: r-help at r-project.org
> Date: Sunday, November 29, 2009, 8:13 PM
> On 11/30/2009 03:22 PM, Tim Clark
> wrote:
> > Dear List,
> >
> > I am trying to get a basic plot to show a continuous
> range of fill colors.  It is probably easiest to
> demonstrate.  I would like a legend like in the
> following example:
> >
> >
> Satellite.Palette<-colorRampPalette(c("blue3","cyan","aquamarine","yellow","orange","red"))
> > require(fields)
> > image.plot(volcano, col = Satellite.Palette (500),
> legend.lab="Scale")
> > contour(volcano, levels = seq(90, 200, by = 5), add =
> TRUE)
> >
> >
> > However, I am using the basic plot function.  So
> far I have figured out how to remove any space between the
> colors using the y.intersp call in legend().  Now I
> need to somehow plot the legend so that it 1) fits on the
> plotting region, 2) has fewer labels, and 3) doesn't have
> black lines between each color.  The example I am
> trying to get to work is:
> >
> > Sat.Pal<-Satellite.Palette (101)
> > x<-rnorm(100, mean = 50, sd = 50)
> > y<-rnorm(100, mean = 50, sd = 50)
> > z<-seq(1,100, by=1)
> > plot(x,y,pch=16,col=Sat.Pal[z])
> >
> > legend("topleft",
> > legend=seq(0,100, by=1),
> > fill=Sat.Pal[seq(1,101, by=1)],
> > bty="n",
> > y.intersp=.5)
> >
> >
> > I would appreciate any help or suggestions on how to
> get this to produce a legend with "continuous" colors.
> >
> >    
> Hi Tim,
> Have a look at the "color.legend" function in the plotrix
> package.
> 
> Jim
> 
>