[R] background colors in image()

[Romain Francois]

Le 11.08.2005 00:59, array chip a écrit :

>Thanks for the suggestion! It works in a way that the
>entire graph window is in the background color, is
>there a way to only have the plotting area (i.e. the
>area within the axis box in the background color, but
>leave the area outside the axes to be unchanged
>(white)?
>
>Thanks!
>
>  
>
You need to learn how to use par('usr') and argument add in image.
demo('graphics') is one way to learn or look at graph 8 on r graph gallery

R> image(matrix(c(1,2,NA, 1),2, 2))
R> usr <- par('usr')
R> rect(usr[1], usr[3], usr[2], usr[4], col="cornsilk")
R> image(matrix(c(1,2,NA, 1),2, 2),add=TRUE)

Romain

>--- Prof Brian Ripley <ripley at stats.ox.ac.uk> wrote:
>
>  
>
>>On Wed, 10 Aug 2005, someone needing to conceal his
>>real name wrote:
>>
>>    
>>
>>>Hi, I am using image() function to plot a matrix
>>>      
>>>
>>which
>>    
>>
>>>has some missing valuies (NA). It looks like, by
>>>default, missing values were drawn in white color,
>>>      
>>>
>>How
>>    
>>
>>>can I change that into a different color, say a
>>>      
>>>
>>gray
>>    
>>
>>>color? I tried to use bg='gray' argument with no
>>>      
>>>
>>luck.
>>    
>>
>>>Anyone has a suggestion?
>>>      
>>>
>>They are not drawn in white: in fact they are not
>>drawn at all, so the 
>>current background (or if transparent, the canvas)
>>is what you see.
>>
>>    
>>
>>>par(bg="yellow")
>>>image(matrix(c(1,2,NA, 1),2, 2))
>>>      
>>>
>>works, for example.
>>
>>-- 
>>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)
>>1 South Parks Road,                     +44 1865
>>272866 (PA)
>>Oxford OX1 3TG, UK                Fax:  +44 1865
>>272595
>>    
>>

-- 
visit the R Graph Gallery : http://addictedtor.free.fr/graphiques
~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~
~~~~~~      Romain FRANCOIS - http://addictedtor.free.fr         ~~~~~~
~~~~        Etudiant  ISUP - CS3 - Industrie et Services           ~~~~
~~                http://www.isup.cicrp.jussieu.fr/                  ~~
~~~~           Stagiaire INRIA Futurs - Equipe SELECT              ~~~~
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