R help - Aug 2008 - error in packet 1

Hello, 
I'm Giovanni from ROMA..

I can't find a solution for the error:

"error using packet 1
the y field is not specified and it has not a default value"
(this is my traslation from italian language)

The code is:

pc<-    qqmath(~valori,
        distribution=function(p) qweibull(p,beta,alpha),
        prepanel = prepanel.qqmathline,
        panel = function(x, y) {
             panel.grid()
             panel.qqmathline(y, distribution = function(p)
qweibull(p,beta,alpha))
             panel.qqmath(x, y)
           },
        layout = c( 1,1), aspect = 0.8,
        xlab = "Unit Weibull Quantile", ylab = "D"
    )


Thanks for your regard,
Giovanni

On Thu, Aug 28, 2008 at 3:07 AM, Giovanni Tarquinio
<g.tarquinio at dmbi.org> wrote:
> Hello,
> I'm Giovanni from ROMA..
>
> I can't find a solution for the error:
>
> "error using packet 1
> the y field is not specified and it has not a default value"
> (this is my traslation from italian language)
>
> The code is:
>
> pc<-    qqmath(~valori,
>        distribution=function(p) qweibull(p,beta,alpha),
>        prepanel = prepanel.qqmathline,
>        panel = function(x, y) {
>             panel.grid()
>             panel.qqmathline(y, distribution = function(p)
> qweibull(p,beta,alpha))
>             panel.qqmath(x, y)
>           },
>        layout = c( 1,1), aspect = 0.8,
>        xlab = "Unit Weibull Quantile", ylab = "D"
>    )
Here's a hint:
> args(panel.qqmath)
function (x, f.value = NULL, distribution = qnorm, qtype = 7,
    groups = NULL, ...)

panel.qqmath() does not have a 'y' argument, which should tell you
that qqmath() does not pass a 'y' argument to its panel function.

-Deepayan