Interaction plot type=o

On Sep 30, 2011, at 2:16 AM, Petr PIKAL wrote:

David,
thank you for your reply

I tried this
attach(mtcars)
interaction.plot(cyl, gear, mpg, type="o", pch=5:8, lty=1 )

but I got this error:
Error in match.arg(type) : 'arg' should be one of "l", "p", "b"

and in ?interaction.plot, "o" it is not listed in type arguments.
Is there any other way to force it to take the argument?

As David suggested you need to change code for interaction.plot. If  
you
write

interaction.plot

you will get the code

interaction.plot

function (x.factor, trace.factor, response, fun = mean, type = c("l",
   "p", "b"), legend = TRUE, trace.label =
deparse(substitute(trace.factor)),
   fixed = FALSE, xlab = deparse(substitute(x.factor)), ylab = ylabel,
   ylim = range(cells, na.rm = TRUE), lty = nc:1, col = 1, pch =  
c(1L:9,
       0, letters), xpd = NULL, leg.bg = par("bg"), leg.bty = "n",
   xtick = FALSE, xaxt = par("xaxt"), axes = TRUE, ...)
{.......

Copy it into some suitable text editor (not Word please) and change it
according to your wish.

You can do it at the console on both the OS versions of R I have used.  
just copy the code and paste. Add the "<-" and the ,"o" and hit enter.  
Piece of cake.

I would start with adding "o" to type in function
definition and see how it behaves.

I tested it. Worked as expected.

Then you can copy the whole code to
your modified function e.g.

my.int.plot <- function(x,....

and call
my.int.plot(cyl, gear, mpg, type="o", pch=5:8, lty=1 )

Regards
Petr

Thanks
Claudio

On Thu, Sep 29, 2011 at 9:00 PM, David Winsemius

<dwinsemius at comcast.net>wrote:

On Sep 29, 2011, at 7:22 PM, Heverkuhn Heverkuhn wrote:

Hello,

I was wondering if there is any equivalent of interaction.plot  
that allow
you to set type="o"
I tried to use interaction.plot and I have a gap between the  
symbols of
the points and the line.

If it's OK to have the lines going right though the symbols, then  
go ahead,
hack the code. All you need to do is add ,"o" to the type  
arguments in the
argument list. The code's not hidden or anything that gets in your  
way.


David Winsemius, MD
West Hartford, CT

David Winsemius, MD
West Hartford, CT