R help - Feb 2005 - two line plot title with expression problem

Dear R-users,

I am having a problem formatting a two line plot title with the first line
text and the second line an expression. I can?t get the second line
expression to line up with the first by starting at the LHS of the line.

A simple example illustrates the situation.

x<-seq(-5,5,length=100)
f<-function(x) x^2-x-1


For a one line title the following works fine?

plot(x,f(x),type="l")
title(expression(paste("Golden Section 
",fn:(phi^2-phi-1)),sep=""))

but when attempting a two line title as follows--

plot(x,f(x),type="l")
title(expression(paste("Golden Section\n 
",fn:(phi^2-phi-1)),sep=""))

the second line containing the expression for phi is indented,
to the right, starting immediately after the position of the end
letter of the first line.

If the second line were to be text, this would not be a problem.

How can I format the title so that the expression starts immediately under
the first line?

Thanks for help.


John.

[John Wilkinson : wilks at dial.pipex.com]

John Wilkinson (pipex) wrote:
> Dear R-users,
> 
> I am having a problem formatting a two line plot title with the first line
> text and the second line an expression. I can?t get the second line
> expression to line up with the first by starting at the LHS of the line.
> 
> A simple example illustrates the situation.
> 
> x<-seq(-5,5,length=100)
> f<-function(x) x^2-x-1
> 
> 
> For a one line title the following works fine?
> 
> plot(x,f(x),type="l")
> title(expression(paste("Golden Section 
",fn:(phi^2-phi-1)),sep=""))
> 
> but when attempting a two line title as follows--
> 
> plot(x,f(x),type="l")
> title(expression(paste("Golden Section\n 
",fn:(phi^2-phi-1)),sep=""))
> 
> the second line containing the expression for phi is indented,
> to the right, starting immediately after the position of the end
> letter of the first line.
> 
> If the second line were to be text, this would not be a problem.
> 
> How can I format the title so that the expression starts immediately under
> the first line?
Multi-line expressions are not supported. You can add them by separate 
calls to title(), though:

  plot(1:10)
  title("Golden Section", line=3)
  title(expression(fn:(phi^2-phi-1)), line=2)

or for left-adjustment, try the same with calls to mtext() and 
specifying arguments "adj" and "at".

Uwe Ligges


> Thanks for help.
> 
> 
> John.
> 
> [John Wilkinson : wilks at dial.pipex.com]
> 
> ______________________________________________
> R-help at 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