[R] two line plot title with expression problem

[Uwe Ligges]

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]
> 
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