[R] pixmap question again

[Prof Brian Ripley]

We got this several times, but I did not see a reply.

You mention `slots': the slot access operator is @ not $.


On Wed, 11 Jun 2003, Christoph Lehmann wrote:

> I could load a picture with gray levels only:
> 
> x <- 
> read.pnm("/home/christoph/work/projects/ffa/EPrime/pics_pnm/550_0_1.pnm")
> 
> > x
> Pixmap image
>   Type          : pixmapGrey
>   Size          : 246x192
>   Resolution    : 1x1
>   Bounding box  : 0 0 192 246
>  
> > plot(x)
> works fine
> 
> BUT: how can I get to the slots as "size", "grey", etc.
>  
> calling: 
> > x$grey
> NULL
> > x$size
> NULL
> >
> 
> why this?
> 
> I need to get the grey value of each pixel and average all grey values
> over the whole picture... 
> 
> thanks
> 
> christoph
> 
> 
> 
> 
> 

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
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