R help - May 2008 - mosaic plot of "vcd" package does not stretch with 2-dimension?

Hi,

I like mosaic function of "vcd" package. I have played around it. I  
have found out that mosaic plot  data table is 2-dimension does not  
stretch when you enlarge a mosaic plot. It is okay when data table is  
3 or more dimension. The first one is of 3-dimension table case, and  
the second one is 2-dimension. With the first plot, you can drag  
window to enlarge a plot. With the second, I cannot.

I have gone through the document, but I could not find any specific to  
solve this problem.

Thank you,

Sang Chul

==========================================================music = c(210, 194,
170, 110,
           190, 406, 730, 290)
dim(music) = c(2, 2, 2)
dimnames(music) = list(Age = c("Old", "Young"),
                        Education = c("High", "Low"),
                        Listen = c("Yes", "No"))
mosaic(music)
==========================================================
==========================================================music = c(210, 194,
170, 110,
           190, 406, 730, 290)
dim(music) = c(2, 4)
dimnames(music) = list(Age = c("Old", "Young"),
                        Education = c("High", "Low",
"Upper", "Lower"))
mosaic(music)

Sang Chul Choi <choi <at> biology.rutgers.edu>
writes:
> I like mosaic function of "vcd" package. I have played around it.
I
> have found out that mosaic plot  data table is 2-dimension does not  
> stretch when you enlarge a mosaic plot. It is okay when data table is  
> 3 or more dimension. The first one is of 3-dimension table case, and  
> the second one is 2-dimension. With the first plot, you can drag  
> window to enlarge a plot. With the second, I cannot.
> 
 
> ==========================================================> music =
c(210, 194, 170, 110,
>            190, 406, 730, 290)
> dim(music) = c(2, 2, 2)
> dimnames(music) = list(Age = c("Old", "Young"),
>                         Education = c("High", "Low"),
>                         Listen = c("Yes", "No"))
> mosaic(music)
> ==========================================================> 
> ==========================================================> music =
c(210, 194, 170, 110,
>            190, 406, 730, 290)
> dim(music) = c(2, 4)
> dimnames(music) = list(Age = c("Old", "Young"),
>                         Education = c("High", "Low",
"Upper", "Lower"))
> mosaic(music)
Not really: note that the images resizes correctly, it just keeps its square
aspect-ratio.

vcd is so strongly modularized that it can be difficult to find the information
required. Check strucplot, where it says:

strucplot
keep_aspect_ratio 	logical indicating whether the aspect ratio should be
fixed or not. If unspecified, the default is TRUE for two-dimensional tables and
FALSE otherwise.

So try

mosaic(music, keep_aspect_ratio=FALSE)

but think over if that's really what you want. In most cases it makes 
sense to keep the square aspect for 2x2 cases 

Dieter

On Fri, 2 May 2008, Sang Chul Choi wrote:
> Hi,
>
> I like mosaic function of "vcd" package. I have played around it.
I
> have found out that mosaic plot  data table is 2-dimension does not
> stretch when you enlarge a mosaic plot. It is okay when data table is
> 3 or more dimension. The first one is of 3-dimension table case, and
> the second one is 2-dimension. With the first plot, you can drag
> window to enlarge a plot. With the second, I cannot.
You need to set
  keep_aspect_ratio = FALSE
This is described on the man page for strucplot() (which is the workhorse
function behind mosaic()):

keep_aspect_ratio: logical indicating whether the aspect ratio should
          be fixed or not. If unspecified, the default is 'TRUE' for
          two-dimensional tables and 'FALSE' otherwise.

hth,
Z
> I have gone through the document, but I could not find any specific to
> solve this problem.
>
> Thank you,
>
> Sang Chul
>
> ==========================================================> music =
c(210, 194, 170, 110,
>            190, 406, 730, 290)
> dim(music) = c(2, 2, 2)
> dimnames(music) = list(Age = c("Old", "Young"),
>                         Education = c("High", "Low"),
>                         Listen = c("Yes", "No"))
> mosaic(music)
> ==========================================================>
> ==========================================================> music =
c(210, 194, 170, 110,
>            190, 406, 730, 290)
> dim(music) = c(2, 4)
> dimnames(music) = list(Age = c("Old", "Young"),
>                         Education = c("High", "Low",
"Upper", "Lower"))
> mosaic(music)
>
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