[R] crosshair in scatterplot to mark special points

From: Mike R <mike.rstat_at_gmail.com>
Date: Mon 13 Jun 2005 - 16:52:45 EST


In a plot on an X11 device, I'd like to mark a few points with a large thin "crosshairs". By "mark" I mean: draw the crosshair on the plot.

The two unsatisfactory methods that I have are:

METHOD 1:
   points( x, y, pch="+" ,cex=2)

METHOD 2:
    line(xa, xb, y0, y0)
    line(x0, x0, ya, yb)

Method #1 produces a crosshair with fat lines. It is not possible to adequately scale the "plus-sign" for my purposes, due to messages like:

   X11 used font size 34 when 42 was requested

Method #2 produces a thin crosshair, but it is difficult to get the two crosshair lines to be of the same physical length on the device. the lines also change length when i change/resize the device.

Thanks in advance for any help or suggestions,

Mike

platform i686-pc-linux-gnu

arch     i686             
os       linux-gnu        
system   i686, linux-gnu  
status                    
major    2                
minor    1.0              
year     2005             
month    04               
day      18               

language R

R-help@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 Received on Mon Jun 13 16:56:28 2005

This archive was generated by hypermail 2.1.8 : Fri 03 Mar 2006 - 03:32:33 EST