(no subject)

---------- Forwarded message ----------
From: "pir2.jv" <pir2.jv at wanadoo.fr>
To: Roger.Bivand at nhh.no
Date: Thu, 28 Sep 2006 16:42:13 +0200
Subject: Re: [R-sig-Geo] (no subject)

Le 28 sept. 06 ? 16:18, Roger Bivand a ?crit :

If you say ls(), do the names of any of the objects begin with plot?

ls(pat="plot")

[1] "BBplot"             "Bplot"              "draw.plotmath.cell"
[4] "plot"               "plotG"              "plotM"
[7] "plotx"              "plotxx"

plotx, plotxx, plotG and plotM are functions of mine. Is there a
problem ?

The problem is that your local function plot is masking the one which
understands that "SpatialPolygons" objects have their own method
and need
to be sent there, so yes, at least your local plot is the problem. The
standard advice if you have a number of functions is to write a
package
with a NAMESPACE, and that will protect you from R not choosing the
one
you intended.

Why would be my function plot local ? It is not.
I removed the others

============

 > plot

function (x, y, ...)
{
     if (is.null(attr(x, "class")) && is.function(x)) {
         nms <- names(list(...))
         if (missing(y))
             y <- {
                 if (!"from" %in% nms)
                   0
                 else if (!"to" %in% nms)
                   1
                 else if (!"xlim" %in% nms)
                   NULL
             }
         if ("ylab" %in% nms)
             plot.function(x, y, ...)
         else plot.function(x, y, ylab = paste(deparse(substitute(x)),
             "(x)"), ...)
     }
     else UseMethod("plot")
}
<environment: namespace:graphics>

=============================

Jacques Vernin