overlay points on plot

Brilliant!   Why the double brackets though?

thanks

femke


----- Original Message ----- 
From: <james.holtman at convergys.com>
To: "femke" <femke at geog.umd.edu>
Sent: Wednesday, February 18, 2004 1:58 PM
Subject: Re: [R] overlay points on plot


 

have you tried:

points(v[[2]],v[[3]])

<r-help at stat.math.ethz.ch>
 

                     Sent by:                     cc:
                     r-help-bounces at stat.m        Subject:  [R] overlay
   

points on plot
 

                     ath.ethz.ch


                     02/18/2004 13:03







Dear R-help list,

I'm trying to overlay a number of data objects in a plot.  Following an
earlier example on the list I've created an empty plot as follows

   

xlim <- range(as.numeric(c("0","10000")))
ylim <- range(as.numeric(c("0","25")) )
plot(NA, xlim=xlim, ylim=ylim, xlab="distance", ylab="semivariance")
     

However when I try to plot something on it, I get the following error:

   

points(v[2],v[3])
     

Error in as.double.default(x) : (list) object cannot be coerced to double

A sample of my data looks like the following V[2]:

      gamma
1   0.040000
2   0.582500
3   1.574545
4   7.126500
.....

and V[3]:

       dist
1   470.0426
2  1045.6365
3  1607.1936
....


Does anyone have any idea how to fix this?

Thanks very much,

femke
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