overlay plot question

-----Original Message-----
From: r-help-bounces at r-project.org 
[mailto:r-help-bounces at r-project.org] On Behalf Of David Kaplan
Sent: Wednesday, February 04, 2009 5:25 PM
To: r-help at stat.math.ethz.ch
Subject: [R] overlay plot question

Greetings all,

I have two logistic plots coming from two calls to plogis.  
The code is

.x <- seq(-7.6, 7.6, length=100)
  plot(.x, plogis(.x, location=0, scale=1), xlab="x", 
ylab="Density",  main="Logistic Distribution: location = 0, 
scale = 1", type="l")
  abline(h=0, col="gray")
 

.y <- seq(-7.6, 7.6, length=100)
  plot(.x, plogis(.x, location=2, scale=4), xlab="x", ylab="Density",
  main="Logistic Distribution: location = 2, scale = 4", 
type="l")  abline(h=0, col="gray")
 
 remove(.x)

 remove(.y)


I would like to overlay these on one plot.  Notice here the 
y-axis is different.  But I would like to axis to be 0 to 1 
as in the first plot.

Any suggestions would be greatly appreciated.

Thanks in advance,

David


--
==============================================================
=========
David Kaplan, Ph.D.
Professor
Department of Educational Psychology
University of Wisconsin - Madison
Educational Sciences, Room, 1061
1025 W. Johnson Street
Madison, WI 53706

email: dkaplan at education.wisc.edu
homepage:
http://www.education.wisc.edu/edpsych/default.aspx?content=kaplan.html
Phone: 608-262-0836