[R] Matrix as input to xyplot {lattice} - proper extended formula syntax

[David Winsemius]

On Sep 6, 2009, at 12:51 AM, David Winsemius wrote:

> I'm not exactly sure what structure df has. Here's my effort to  
> duplicate it:
>
> df <- data.frame(y=matrix(rnorm(24), nrow=6), x=1:6)
> > df
>         y.1        y.2        y.3        y.4 x
> 1  0.1734636  0.2348417 -1.2375648 -1.3246439 1
> 2  1.9551669 -1.1027262 -0.7307332  0.3953752 2
> 3 -0.7645778  1.6297861  0.4743805 -0.4476145 3
> 4 -0.5308756 -0.5246534 -0.3854609 -1.6097777 4
> 5  0.7406525 -0.8691720 -0.8194084  1.6122059 5
> 6 -0.9625619 -1.0774165  1.0760829  0.3659436 6
>
> And this seems to accomplish the desired task. Presumably you have  
> assigned off-stage the value of title to a meaningful character  
> string?
>
> > p <- xyplot(y.1+y.2+y.3+y.4 ~ x |1:4, data = df, main =  
> "title" ,layout=c(1,4) )
> > p
>
For the record, the xyplot call above does not give the desired output  
but Gabor's method does. I'm glad that construction of a sample df was  
useful, even is my efforts a driving xyplot with a surrogate grouping  
sequence was not.

-- 
David.
>
>
>
> On Sep 5, 2009, at 11:52 PM, Bryan Hanson wrote:
>
>> Hello R Folks...
>>
>> I have a list with the following structure:
>>
>>> str(df)
>> List of 3
>> $ y    : num [1:4, 1:1242] -0.005379 0.029874 -0.023274 0.000655  
>> -0.004537
>> ..
>> $ x    : num [1:1242] 501 503 505 507 509 ...
>> $ names: Factor w/ 4 levels "PC Loading 1",..: 1 2 3 4
>>
>> I want to plot each row of df$y against df$x, and have each plot in  
>> it’s own
>> panel according to the levels of df$names.  The following works in  
>> the sense
>> that the layout is right, but the y values have clearly been  
>> recycled or
>> skipped in some fashion (and an error is thrown for each panel that  
>> the
>> length of x and y aren’t the same):
>>
>> p <- xyplot(y ~ x | names, data = df, main = title,
>>       layout = c(1, dim(y)[1])
>>
>> In reviewing the extended formula interface in the Lattice Book,  
>> what I want
>> to happen is y1 + y2 + y3 + y4 ~ x | names, outer = TRUE
>>
>> I see two options: figure out a way to create the extended formula  
>> on the
>> fly (and the actual number of rows in y may vary), which seems  
>> potentially
>> tricky, or create a data frame by stacking each row of y and  
>> repeating x and
>> names to match.  This seems like a waste of memory.
>>
>> I’ve looked through the archives and haven’t come across something  
>> quite
>> like this, or at least I don’t recognize it if I have!  Is there a  
>> more
>> elegant way to tell xyplot I want to use each row of y repeatedly  
>> with the
>> same x, in a loop-like fashion?
>>
>> TIA.  Bryan
>> *************
>> Bryan Hanson
>> Professor of Chemistry & Biochemistry
>> DePauw University, Greencastle IN USA
>>
>>
>> 	[[alternative HTML version deleted]]
>>
>> ______________________________________________
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>> and provide commented, minimal, self-contained, reproducible code.
>
> David Winsemius, MD
> Heritage Laboratories
> West Hartford, CT
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.

David Winsemius, MD
Heritage Laboratories
West Hartford, CT