Message-ID: <200304031145.GAA20022@www6.mail.Virginia.EDU>
Date: 2003-04-03T11:45:05Z
From: Frank E Harrell Jr
Subject: ace with mon=0
In-Reply-To: <Pine.SOL.4.10.10304021710310.16797-100000@shakespeare.helios.nd.edu>
-------------------
>
> I was wondering whether someone can help me understand the
> following behavior of the ace-function:
>
> When ace is called with mon-parameter set to zero, R gives the
> message "response spec can only be lin or ordered
> (default)" and returns immediately. However, according to the help
> file mon=0 requires the response transformations to be limited
> to monotonic transformations.
>
> For instance, the following call of the ace-function will not be
> evaluated if one gives mon=0
>
> TWOPI <- 8*atan(1)
> x <- runif(200,0,TWOPI)
> y <- exp(sin(x)+rnorm(200)/2)
> a <- ace(x,y, mon=0)
>
> Why does mon=0 not work and how should one interpret the message
> "the response spec can only be lin or ordered" ?
>
> Any help will be greatly appreciated,
> Christof
>
> Christof Schuster
> University of Notre Dame
> Department of Psychology
> 103 Haggar Hall
> Notre Dame, IN 46556
I use ace and avas quite a bit and have found a few tiny bugs such as
that one. I reported these bugs to the R bug list about a year ago
and await corrections. As you said, ace does handle nonmonotonic
transformations of Y; you just have to turn off that error message.
Frank Harrell