>>>>> On Tue, 30 Sep 2003 09:38:31 +0100, >>>>> Barry Rowlingson (BR) wrote:
> Christoph Lehmann wrote: >>> plot(pixmapGrey(fmri.vtc[,,slice,volume])) >>> identify(fmri.vtc[,,slice,volume]) >> >> warning: no point with 0.25 inches >> >> >> pressing the right mouse button I get: >> numeric(0) >> >> what is the problem here and how can I solve it? > The problem is that there is no method for identifying points on a > pixmap (and anyway, you are feeding identify() a matrix). > You'll need to write an "identify.pixmapGrey" function. This would do > something like use the 'locator()' function to get clicks on the screen, > and then it would compute which grid cell the coordinates of those > clicks were in. pixmap objects store enough information for you to work > this out from the attributes - look at the 'bbox' attribute for example. > It would make a nice addition to the pixmap library. Although one > thing that just suprised me was that the different flavours of pixmap - > pixmapGrey, pixmapIndexed, pixmapRGB - dont all inherit from a 'pixmap' > class, But they do, and class "pixmap" has the necessary geometry information, i.e., size, bounding box and resolution of the image. > which might make it easier to write a single identify function > for all the types. yes, shouldn't bbe too hard (all contributions welcome). .f ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help
